I wanna give you a big hug!
I understand how you feel - I'm very extrovert and sociable, but my little brother was exactly the same way as you, for years and years. Then he went to the gym, got built like a brick shit house, and is now on the verge of arrogant. Let golf be your gym!
Let me preface (the remainder of) this post. I'm awful at golf. Crap. Useless. Woeful. Shambolic. Diabolical!!!!!
I go myself, and luckily enough, I'm never paired up. Like one of the responders above, I find soft spots in the course schedule, and having been there a few times before, I now know when it's busy and when it's not. Even on 23 degree days in the middle of summer, it'll not always be busy.
I always let people play through; today, I did the usual, and let two two-balls go in front. On the second tee, I caught up with them, and one asked me if I'd like to play along. I'd seen they were both beginners, like me - no handicap - and so I said yes. Duffed my first well left, took a second and it was crap. But it went past the ladies tee so I played on. And you know what? I had the best round ever with these two strangers (became three on the fourth hole). They weren't great, neither was I, but it was such great fun!
And the great thing is, you don't have to talk loads - you're not sitting having a chat, you're playing golf. You don't need to worry about filling in silences, or thinking up topics of conversation. You're playing golf! When you hit a slice, that'll be the topic, when you hit a 200yd carry over water, that'll be the topic, etc. etc.
Anyway, to conclude -
enjoy
being paired up. It's an opportunity to meet new playing partners; at the end of a round, don't be afraid to offer your number, or ask for theirs. If you've had a fun round together, they'll not say no.
Sorry for the length.
andy.
Edit: And btw, if you're ever in Belfast (unlikely, I know) let me know! Only my work colleagues play golf, none of my friends!