Help - depressed, have no friends, 18 years old in first year of uni?

I honestly don't know why I have resorted to posting my thoughts here but I think I just need to vent as I feel so incredibly lonely and I am crying right now. I'm 18 and in my first semester of my first year in university - and I had to move away from my family into a college on campus. My course load is very hectic and i'm overly stressed because my exams are very soon and I havent studied properly - let alone learnt the new material. I just want to give up frankly. I've tried so hard in the past but keep failing in everything I attempt. My brain seems so foggy I cant remember anything that happens and I struggle a lot to learn new things. I'm also living on campus and the people here are making me feel terrible - they either make horrible comments about me or just make me feel like crap because of how awesome they are and how much they are living their life to the max. They hate it that I never go out and do anything - but I really want to just cannot because I'm getting really worried about everything (I also have social anxiety and am extremely shy and stupid) - especially because my exams are so close and I don't know anything. I'm not very smart at all - in fact i've been called dumb, stupid and been made fun of many times in relation to my intelligence. Therefore I hate everything about myself and hate university life too. I can't even write properly now as my thoughts are all jumbled and i'm struggling to even think. It feels like everyone has turned against me and i've been feeling like such crap and like such a loser since I started uni at the start of the semester. I keep thinking of the future and end up crying because I really feel like i'm going to still be this sad, person with no life and no achievements but I really really want to change . I'm not doing well academically or socially - not easing into the college atmosphere where I live here at all so I consequently don't even see why I should live if I have nothing and I am nothing :( Please any advice is appreciated thanks