so what changed in the last 2 weeks? Just another thought of my own...is this a career or just money to pay the bills? If the pay is the same and you show up from 8 to 5..do your job
(whatever they decide that is for the day) then go home, then enjoy the money for less work. However, if it is in your opinion as bittenkiss pointed out workplace bullying by all means break it off in his ass

don't worry mate, jobs are shit for the rest of us too

seriously, if its that bad, you could quit or if you decide to stay start to keep a diary of the bad stuff that goes on. Workplace bullying is a serious problem, and the only way to deal with it effectively (note: curling up or otherwise thinking you'll get by is not effective, not in the long run). Once you keep a diary of all the crap you get dealt, then you can take it to HR when you're really had enough and they can deal with it. Turning up without any 'evidence' will not let them deal with it properly - it becomes easy for the bully to say it was all just misunderstanding and they'll try to communicate better with you. Turn up with a long list, and you'll get some form of satisfaction, even if its just to rub the bully's nose in it on your way out the door.

You should also try to have a formal chat with him to express your dissatisfaction, possibly ask for a transfer to another department if possible. Or, go see HR and just have an informal chat with them - but note that they are not "your friends", they will be more concerned about the company, not your welfare (just so you don't get any expectations that they'll back you straight away)

Note, if he's doing this to you today, chances are he'll be doing it to someone else sooner or later. You have a duty to deal with it now.

That must have been an interesting party for sure.