Thinking about buying new irons

[lisevolution]

So I recently got back into the game after about 10+ years off and I'm officially readdicted to this sport.  I picked up a used set of Nike Sumo2 Hybrid Iron's 5-7h, 8i, 9i, PW, AW, SW.

This is the thing, I definitely have some issues with my swing that I'm working on such as swinging inside out and keeping my head steady.  I definitely fall back on my tee shots too but that's a whole other story.  In any case the thing that I've noticed and is what has me thinking about new irons is I essentially hit them all about the same distance regardless of the club.  The clubs also have a sort of dead feel to them, very damp in the hand which I really don't like.  When comparing them to my 3h TM Superfast I picked up or even the fairway woods their is a noticable difference in club feel and overall distance.

Do you guys think my issues are more tied to my swing problems or should I seriously be looking at new irons?  I do like that for the most part they fly straight when I hit them but if there's no change in distance I feel like I have 6 useless clubs in my bag...