miserable!!!

This may sound a bit weird, but... Is it hard for 你 to breathe? Try to breath in slowly, and really deeply. Then breathe out again. 更多 often than not, this will make 你 feel alot better.

And I get what 你 mean. I'm in a likewise situation myself. What I tend to do to relax, is lie on my 床, 床上 and doing nothing, and just listen to calm music. I excersise alot too, often with others. My 建议 is to 加入 a group excersise. It sounds tiring but believe me, Excersising is a great way of relaxing, and meeting new people.

And this may not sound very helpful but, I feel for you! ;)

Depression can come at any age and for any reason. Small trivial things can trigger and major depression attack, even something as small as not having your favourtie 衬衫 washed and dried in time can get some people down in the dumps so bad they want to end their lives.

It sounds to me as though 你 have very severe depression. I'm not a medically expert, i'm just telling 你 what it seems to be to me and my experiences. I suggest 你 go see your doctor, explain how you're feeling and could he please see if any anti-depressants will help and also see about councelling. 你 may not think 你 actually have any problem other then this depression, but it has to have a reason, and a psychologist can help unearth that to get 你 on the road to recovery.

Is the dream job actually what 你 want? It seems like it is, but is it really when 你 get right down to it? Is the pressure of getting all the work done and not connecting with your peers getting to you?
if the workload is too much, try talking to your tutor and ask their advice. As for the problem about not having any friends, 你 have to admit that is partly your fault for not engaging them in conversation. Take it slowly, pass someone in the hall and say hi. If they're in the same subject and you're not sure about something ask for their help etc.

To calm yourself, 你 can always take a big breath in, and then exhale longer then 你 inhaled. This will make your 心 泵 slower, calming your nerves and shutting of your adrenilin.
Calming teas, fresh fruits and veg, plenty of sun-shine and oily 鱼 once 或者 twice a week such as 三文鱼 或者 tuna, can all help with a well-being inside 你 :)