<human>: Can you provide a brief overview of the text?

I have a group of friends and over the time of our friendship, i realized I don't have much in common with them. I am very motivated in terms of my education and always felt guilty every time I used to go out drinking with them etc.

They are the type of guys who talk shit behind everyone else's back, drink and smoke excessively, and never really study for their degree.
I'm the opposite infact, I rarely drink much, don't smoke, and am very motivated to get as high grades as possible.

I noticed over the past year of 2 there is some snickering and exchanging of glances occasionally when I am talking. When I started noticing it more, i gradually stopped hanging around with them as much, as i deeply felt hurt and anger at their behaviour.

One of the guys is in my class, so it's not like I can completely withdraw from them. He irritates me too as I have done him favours and helped him with work (and he has also done some stuff for me too) but he's one of the ones laughing. They used to always call me to hang out and stuff but after I noticed them laughing at me, I kept declining to chill with them, so now I only see them around uni, which is almost everyday. 

It's very difficult for me to open up around them as I am pissed of at them, so they think I'm just this completely closed off guy, with no sense of humour and awkward to be around. I see them around uni and stuff so it's not like I can just not hang around with them (I have 3 years of school with them) and everytime we have our small talk I end up going home with my blood boiling with anger. Either they are exchanging looks with each other in my presence, and asking me why I'm so serious all the time but I just don't even know how to react with them any more

I'm not like this with any other of my friendship groups, I am known to be a laid back fun guy and I always have an awesome time with them - but this friendship group at uni makes me so depressed sometimes I don't know if I can handle another 3 years with them around.
<bot>: Friends laugh at me behind my back, even sometimes in front of me. Stopped hanging around with them but still see them around uni. Don't know how to handle them as I have another 3 years left of uni