All I can say is, I used to be like that. Your approach to professional relationships is healthy as far as I can make out ("1-3 co-workers ... All others I keep at a distance"). The only thing I'd suggest you develop upon is the relationships outside of work, keeping things lightweight (superficial, even) if you find people draining. What's important is to just be there. Socialising is like a muscle the more you use it the stronger, more enjoyable, and easier it will be to use it.
