Now that I am totally alone in the UK and not with someone ... I am begining to wonder why I shouldn't just get on the airplane and .... go home!
I dont know you, but from reading your posts, I cant see how you would think anything other than this. Your experience in the UK wasnt what you thought it would be, you dont like the UK or the people who live here, you still call the US "home", and you are so right that a job (no matter how great it is or even if the salary is outstanding) doesnt make up for having people around who love and care about you.
I dont want this to sound horrible, but I am afraid it might, so my apologies in advance, but when someone is as bitter and guarded as you are (and you have every right to be) you are not going to come across in the best way to make any friends, so I cant see your situation improving drastically enough to make you happy in the UK.
As much as you may not want to "go home with your tail between your legs", it may be the best thing for you.
Good luck.