Back Down, God damn it!!!!!!!

Ok I recently posted on my relapse but didn't really explain much.
Basically, on Sunday October 3rd I moved away to uni' for the first time. Two weeks earlier I'd smoked pot (like an idiot. It's a long story), had a huge panic attack, felt very depressed for a few days. With some good R n' R, I recovered quite easily. I was still a bit fragile perhaps.
Anyway, that day I was experiencing massive amounts of anxiety, including several full blown panic atacks. Felt terrible when I got to my new flat. The flat itslef was hideous, not the kind of place you want to be left when you are in that sort of state.
Met my flat mates. Went drinking that night. The drink seemed to help with the anxiety, but I still felt depressed.
The next day I felt very depressed, anxious and dp'ed. So I went drinking again that evening, this time it didn't help. Stayed up talking till three am. A new flat mate was talking about bad drug experiences he'd heard about. He was describing one particularly 'far out' experince he'd read about. Then I totally flipped out, had the worst panic attack ever. Ran out of the flat in my pyjamas and just kept sprinting. The fear just got deeper and deeper, I was convinced I'd gone beyond the point of no return, I was beyond any form of hope. I was going berserk. Anyway eventually I became so exhausted that I collapsed in my bed.
Woke up several times that night in a horrible state. The next day I was truly zombified, huge dp/dr etc.
Was extremely depressed for the next week or so.
All those old f*cked up thoughts I used to have two years ago when I last felt this bad have allcome back. Self observation is my only past time. I keep getting lost in my mind. I can't believ this is all happening again.
Just a few weeks ago I was almost cured. I hadn't actually had an intense dp episode for almost a year and a half. The last time I was lost in a deeply obsessive state was half a year ago (and at least that was a sort of tangible logical obsession). Last summer was simply amazing. I was still experiencing dr from time to time, but for the most part I was really good (read my story in the story section). Now I don't know where/what I am. MY minds a huge mess. Thoughts go round and round in circles. I feel like a dog chasing it's own tail. You know when you're not evn sure what it is that's making you feel so anxious, so you feel you have to explore every horrifically imaginative possibility. In some ways I wish that I was just obsessed/afraid of one particular thing.
I feel I have to monitor every thought and emotion, then rationalise it. The thing is, I have insight this time. I know why my mind is working the way it is. I know that after that terrible panic attack I had, my mind imploded. Went into code red, every brain cell on alert, as though there were an escaped convict in my mind.
Part of the problem is my environment. This university is depressing. My accomodation is depressing, and the two mile walk on to capmus that I have to do at least four times a day is very depressing. Being surrounded by superficial friends whom you have no interest in talking to is depressing. The f*cking fluroscent light that seems so concerned with illuminating every f*cking pore on your face, that infests every indoor environment in this God forsaken place. It's a far cry from the tranquility of my home, or that of my relatives, or Thailand or Amsterdam. Yes the past few months have been nothing but romantic hedonism for me( and I do apologise for any melodramatic posts during that period, cos' I was in fact feeling great), which is what makes this all the more galling for me.
I just can't seem to get out of my mind.
Any thoughts or advice would be greatly welcome, thanks.