Year 12s: what will be the first way you research your future options? >>

What would you do?

Ok i turned 19 this year and the last three years have been rich with highs and lows.
I start saying that i'm on my last year of college, i'll get a sort of electic engineer degree, however i don't feel really confident about my skills in this sector, because basically i had many trouble during my three years course. Here's the story:

First year: i was 17 in the second half of the school year and decided to apply for a scholarship for an exchange year in England. I had a miserable life, few friends, no girls around. Basically i didn't expect anything more than i had. I think i had low self esteem, however i managed to get the scholarship!

The second year was the best of my life. I was on exchange in south England with a group of 11 other students. For the first time i really felt good, i felt involved in a group of people, had befriended many girls and got in a relationship with one. School was peaceful and learning-oriented and the time passed very quicly. I had some lows back then too, i missed my family sometimes, but i think it's normal.
Obviously being abroad i missed the second year of my italian degree couse, so i was a lot behind, however i got back in the third year!

Third year: first half i struggled to catch up the main things of the fourth year, but i did it. I was stressed as hell and the class environment didn't help at all: many disruptive students in my class, teachers screaming all the time and no more free period like in sixth form. I wanted to have high grades but then realised that it wasn't worth it, because of the stress and injustice in the mark scheme.
So now my grades are high enough only to get the hell out of that course, i sadly adapted myself to this low general standard!

Also now i'm stressed and i think i'm getting anxious, i don't go out, i sleep all the time, i'm frustrated and have no will to recreate a life here, because it feels "all known" and all wrong! I'm gettind used to do nothing, and this scares me.
My relationship with my parents is also complicated; we're not a close family, my mum is always angry and spends all her time watching TV, my dad is always smoking in silence and i'm on the computer. I don't know whether this hate comes as a consequence of my bad mental level, or because i'm too close to them.

So here's the harder bit: i have developed a huge interest in physics, and i'd really love to study it at uni, which would be in my home town. However math is fundamental in physics and i saw my math grades drop down a lot because of the weird mental status i have.

So what would you do? Would you try hard to get a degree or pursue happines and build a life from scratch abroad??

sorry for the lenght of the post and thank you for any advice!