Failing miserably.. Chunks are going to knock me out of the game.

I can't hit the ball. Simple as that. I take a week off due to work and I simply have lost all fundamentals of the golf swing. Its absolutely terrible and I cant get past it. The chunks. This is a very severe case, Im getting so much ground. I try to focus on my take away, swing plane, and hip rotation/weight movement and I just cant seem to diagnose it. If I don't chunk it 100 yards it goes screaming across the ground at the range or goes looping to the right. I'm a right handed golfer. Im hitting 5 irons like 100 yards. So frustrated and I just cant figure this out. From my best golf round of my life at the beginning of the year, to the worst swing of my life right now. Any ideas? Ill try to post a video of my swing soon

Been there.  Without seeing your swing, I would say there's a 90% chance it's one of the three following faults:

1. Swaying in the backswing: video your swing from face on.  look at where your trail hip is at address.  If it moves laterally away from the ball at any point, you're swaying.  Takes incredible timing to get back to where you want to be at impact.  Make sure you're rotating instead.

2.  Flipping the club at the ball: if the club head gets to the ball before your hands, you're flipping.  Big reason for chunking/topping the ball (same exact swing fault, just a split second difference in timing).

3.  Weight forward at impact.  Get to your left side before impact.  I like to feel like I have close to 90% of my weight left when I actually strike the ball.

I'd be surprised if it wasn't one of these.  Once you get it down, you'll get to a point where you expect consistent contact.  Now, getting the ball to go where you want...different ball game.

Sound and Fury has provided an excellent explanation.  I would add as an "overview thought" that most of my students "mishit" because they do not continue through the shot with their trailing side (for right hand golfers I mean their right hip and their right shoulder).

When the body turn quits or falls behind in a golf swing the hands/arms will tend to wander off plane and release at the wrong moment.  Try to feel as though you are "hitting the ball with your trailing right side".  A feeling that your right side and the release of the club head are completely in sync... they both "explode" through impact at exactly the same moment.  Make sure neither of them quits at impact or slows before impact... continue both to a complete turn through the impact area and on to a complete finish.

Do not do anything with your upper body (hands, arms, shoulders) to accomplish this feeling.  The upper body is just along for the ride.  Take the club back and through with your lower body only... the upper body remains relaxed and compliant.  Work on your lower body motion, balance and tempo so it provides the ideal support for the upper body to be in exactly the right positions throughout the complete swing... without having to manipulate parts of your upper body (hands, arms, shoulders) parts to facilitate a less than optimal lower body motion.

The keys to consistent ball striking are almost entirely to be found below the belt.

P.S.  Never give up... just be grateful you have the health and opportunity to struggle in such a meritorious endeavor.

This.  Especially when it comes to the flips.  At one point I realized I was flipping at the ball, so I tried to consciously hold off releasing my wrist cock.  Still not going to work. Flipping is a symptom, not a disease.  The disease is a stalled pivot, or quitting on the shot like Imeubu said.  When you get to the top, you gotta seriously fire your right side through the ball (which starts with lateral move towards the target juuuuuust before you reach the top of your swing).  Do that while keeping your hands passive, and your wrists with unset, thereby snapping the clubhead through impact.

You will absolutely know when you get it right. The sound and ball flight will be quite different.

I have real problems keeping my arms/hands fully relaxed. What happens a lot if I focus solely on my lower body is I come through with my club face wide open and hit straight right.

Love this drill, do it every time i am at the range to start out before hitting full shots. It really helps me nail the impact conditions. I would also mention, i had a hard time with this drill early on, i was hitting shots fat, or very steep. I found out i need to just rotate the hips and body thru and really let the body do the work instead of the hands. When i do that the club comes in much shallower with amazing contact. I can even do this drill with the ball placed outside my front foot, and the effect is a monster high push draw. It was really cool to hit a ball first that far forward, if you can get that to happen, then you can hit the ball first at its normal position. I like to spend the last 10 minutes of each range session hitting stupid shots. Its kinda a work down, so i tried that one, and it worked :)

This EXACT same thing is happening to me right now.  I swear to you, what you described is exactly what I am doing.  I am just digging up the ground and its ridiculous.  Its so embarrasing because I am a very good athlete and now I can not do ONE thing with any iron at all.

when this happens - I really slow it down.   Easy backswing, smooth tempo down swing.    Focus on the ball - really stare it down

I recently went through a patch where I was chunking and hitting really fat.  The majority of the time when that happens to me it is because I was trying to use all arms without rotating my body.

A swing thought that helps me get a proper rotating and weight forward is to focus on the feel and idea of my forward arm leading the club through the swing.  For some reason this gets my body rotation in sync for me.

I hate to say this but you, and I, need to dis-engage our forebrains on the golf course. That's the part of our brain which is concerned with conscious thought, like thinking about the hands, the body rotation, the power accumulators,  the need to slide the hips, the desire to strike the ball and make it move 230 yards straight as a string.  All these thoughts, conscious thoughts, ruin us as golfers. Good golfers have learned to dis-engage the forebrain and engage the hind brain; usually done best at a young age., Some golfers  never learn to do so, but most of us try to and have very limited success. Hence, the huge market for golf instruction. But how many golf instructors can teach anyone to learn to rely on the hind brain, that part of the brain concerned with balance and timing, among other muscular motions.  Sure, muscles don't have memories but the memory of the motion is stored in the hind brain.    Not to knock Erik's video but i can swing the club very nicely, smooth as silk, at home on the carpet, or on the chipping green but when i need 120 yards, over the water and the wind is blowing in my face, those videos get totally lost and scrambled in my brain.  My forebrain dominates and i smash at the ball as i would a log on the ground. Once, twice or a few times each round we DO dis-engage and can feel the very positive results as the ball behaves beautifully.   How to DIS-ENGAGE on every shot?          Good luck to you my friend, and to me.

Think less, it's important to regain your confidence first, hit an entire bucket with just your pitching wedge aiming at a target like a 100 yards away or whatever. The next time out you'll be coming off that instead of your recent struggles.Being able to address the ball with confidence leads to relaxation which leads to better results, it's the same psychology I used playing hockey, as a goalie I'd have off nights and so much of that is mental,just like golf. Just focus on your strengths for a bit.

+1 for this Drill.   Super drill that I start my practice time with.   Get that weight forward and hitting the ball first into the "noggin" - reinforcement right at the start is great.