I think I need to get some help.
What do you need help with?
I can't do well at college, and my girlfriend is also cheating on me.
I'm sorry to hear you're having a rough time. It's perfectly okay to ask for all the help you need, but I believe it would be great too to try and reciprocate the help back! It's nice to also strengthen relationships while you're patching up.
I know but it's hard for me to get help from people.
Asking for help can be hard, but it's not shameful to get help when it's needed. Confront your girlfriend, and get a tutor for your classes. Make sure you thank whoever helps you by returning the favor or paying for the tutoring.