motivation and de-motivation

I don't know if it's a good place to post it, but I didn't find any better.

So here's the problem;
How is it with your motivation? Who or what motivates you to get better?

I do feel some motivation as I have a lot of contrary feelings. I started my education at the University, broke up with my boyfriend, so it's currently my exboyfriend, but we still attand to the same group at the university and it's too cruel for me to pretend I don't know him or not to help him.
I've changed. I want to improve myself, to do something useful with my life. I want to learn both theoretical and practical things, but I'm surrounded by pepole who don't care...

Last 2 days I spent learning at home. Today I took an exam and everything would be okay if my ex hadn't wanted to crib from me. The feeling he doesn't care and doesn't do anything and then cribs from everyone and passes everything is killing me inside. I can't be so mean and don't help him if I can... but it ruins my motivation and self-esteem.. And I totally can't cope with it. I tell him everytime I won't help him anymore, that he doesn't do anything and blablablabla...

I pretty don't know if it's something wrong with me or with people around me.. Sometimes I really wish I lived in a different place, among different people..

Thnanks in advance for any advices.