Sorry to hear you're having trouble and you're feeling overwhelmed by it.
You have your family and your girlfriend, sometimes that's enough. She sounds like a great girl.
And, dude, don't sweat not getting a job for the time being- I looked at your profile and I see you're in the UK- I live in the Republic of Ireland, so I've even less chance of finding a proper job!

It'll work out, man. Just give yourself some time and some breathing space.
Go away for a weekend with your lady somewhere, might help you re-focus.
Also, if you're having a hard time with your mates, well, true friends never really part.
It's never too late to say you're sorry, and although I realise that's a truism, good friends will forgive.
Just remember:
"This, too, shall pass."
Also- hope this brings a chuckle- http://www.qwantz.com/index.php?comic=198