What's the actual work environment like? I left my previous job when it got too crowded and noisy and I now work in a room with one other guy who only really talks if I talk to him. I interact (both socially and professionally) with colleagues but I'm rarely pushed to. Most of the time I don't have to interact and so when I have to, or feel like it, I can find the energy.

Previous jobs where I've worked in noisy crowded environments have generally left me feeling weary and irritable, made it harder for me to want to do anything in the evenings. In my current job I told my interviewer at the outset that I was an introvert and wanted a quiet environment, and I got it. I can say from experience that when you own it and figure out where you comfort zone is, things get a lot better. Don't try and match the extroverts' level of sociability. You can't, and trying will just leave you demoralised. If people comment on you being quiet, just say "yeah I can be a quiet guy sometimes, that's my nature", or whatever is true for you.

I super disagree with this idea. I was extremely introverted until post college, and a lot of people here were. I think most of the known PUA were too. That's one of the big reasons we end up in this community. There was a point I couldn't really hold a good conversation with people, wouldn't respond appropriately and would stutter when I talked. Bad, bad, bad...

After 6 yrs of working with people and trouble recalling how many women I've done sexual things with... I can get almost anyone to laugh, can talk about almost anything (even things I personally don't enjoy much), and can reason, out-think and explain circles around most people 2 x my age. Yes this is me me me, but I used to be in the same place.

Accepting and saying you are just not good with people is very narrow minded, a self-defeating attitude, unhealthy, and you shielding yourself further from something that you haven't even tried and will push you outside your comfort zone is not a good thing IMO. It's in human nature to have social interaction. There is research that says being social is a human need.

Okay. Perhaps my communication skills could have been better on that one. What I was meaning to focus on is the fact that I, and I presume the OP, will never feel the desire to spend as much time around others as some extroverted people. You can definitely improve your social skills and become good with people, which is obviously what the OP needs to hear (and is completely true). But if you're an introvert you will always be drawn to time alone, a lot more than an extroverted person. There is improving your social skills and manning up and a whole bunch of stuff you can do to improve your situation. But just don't feel bad if you don't want to be constantly going to parties (or indeed spending 40 hours a week in an open plan office).