i hate this feeling

very sien de lo,
actually when the 1st of my college i din plan to know any friends since i din know anyone at there but in an opportunity i have knew my coursemate....
At beginning i feel very fan because one of them too depending on me always follow me whatever co-co i take, group that i take she also wan to follow....
Then, reach sem 2, at beginning having a good relationship with them but until half of the semester, after an incident happened all things had changed.... Sometimes i have a feeling that all of them always boikot me since i have to work after the class, always absent for class, din do my tutorial question but since u all dun wan me then why wan friend with at the beginning?
After i have that friends feeling now only dun wan me?
I have try my best to work our friendship but wat i get?
一次又一次的伤心？
一次又一次的被离弃和遗忘？
actually i wanna ask them did i did something wrong until u all threat me like this?
Sometimes, i got think is it i think too much?
but the words the post on fb and the way thing they communicate make me think like this....(actually i willing to close my fb account i saw thing that make me sad but i cant coz my class reps will post many thing through fb and my other friends oso communicate through fb)
i cant mix with them, on the topic they talk about coz i dun know wat are they talking about......

What should i do?
should i give up to work on this friendship?
or should i stay away from them?
do not mix with them anymore?
in this situation i feel very tired, until now i have no energy to continue it.
Sometimes, they will let me join, or join me in but Sometimes they will leave me alone and din care about me.....
Actually inside their heart do they have a place for me as a friend?