Honestly I would drop out of the frat. I realize you’ll lose a semester’s worth of dues – but why are you paying money to be part of a group that you’re not happy with and that doesn’t particularly like you? If you drop out today, that leaves you 4-5 days to study for your midterm. It’ll be a load off your mind re the lack of time/sleep/drinking.
As far as far as school goes, once you have time again – can’t you set up a more rigid structure – i.e. wake up at 8 am every day regardless of when you have class; go to the library and study/do HW for x hrs a day; go to class. It’s easier to put stuff off in college bc often you’re only being graded on 2 exams a semester – but it is easier to do better if you study/keep up with reading daily.
As far as friends – can’t you take on some activities outside of class (once you drop your frat)? I realize this would have to wait until next semester, but if you find ways to get involved – you’ll have chances to make friends. I’m sure it seems odd that you did so well at Harvard in summer classes, but now Berkeley – your real school – is a struggle, but there can be lots of reasons for that. At Harvard (not clear if you were a HS student or a college student at the time) – you were likely only taking 1-2 classes and you knew you’d only be there temporarily – so you likely weren’t thinking too much about making friends, fitting in etc. and were content to talk to whoever seemed cool enough. It’s different at your own school when you have 4-5 classes and know you’re “stuck” there for 4 yrs – the grind gets old.
If you left Berkley, where would you want to go? Honestly if you are really in your 5th semester as PP said – I’d try to make some changes and see if you can make it work, rather than leaving and starting over some place.