I am absolutely appauled at some of the responses on this page, what sort of people do you think you are?
You can't always get answers that are ones you like to hear - which unfortunately seems to be the root of this problem. You are coming across as a little self-centred (whether intentional or not). Other peoples lives (your fellow crew) don't revolve around your wish for a social life. It's really hard to tell from a distance, but maybe you're enthusiasm to go out and party might be a little off putting to some of the more senior crew? Maybe the isolation it's something to do with how you approach other people and how they interact with you in return?
So your job is a bit boring. Welcome to the world. You have two choices - you make the most of a bad thing by doing things on your own (and a career in BA is hardly the worst thing in the world, or you leave and find some new territory. If you feel that the risk of doing that is worth it, then try it. Fingers crossed that you won't feel the same 6 months down the line at a new airline!!!!