How do I get over my ex boyfrind that cheated on me?

Avoid him. Don't call him and don't take his calls. Block him on Facebook and email. Avoid, avoid, avoid. Fill your time with other, better things and people. It gets better.

You start no contact,get busy doing other things in your life,see more of your family and friends,make plans for yourself.

Breakups are hard and can hurt like hell,but as time passes you do get better and heal and can move on to other relationships,but for now,take time for yourself.

Thank you, but I don't live in the same school district and we were having a long distance relationship and then I found out he cheated on me with my best friend.

Sounds like the first thing you should do is find a new best friend! Long distance relationships are really hard to maintain even in the best situations, where each person is equally devoted to the other. I guess your best hope of getting over it is to give it some time, don't think about it, and be nice to yourself. Sometimes these things don't work out, and it doesn't mean you should beat yourself up over it.

How could you not get over him?? Seriously... forget him and your EX best friend.

It's not so easy to forget. Believe me I am in a similar situation and I am devastated. For me it actually really helped to go out and get my nails done, start tanning and going out with friends more. It made me feel more like I was living life and taking care of myself (usually I never get my nails done or do much "girlie" stuff). Also it may seem wrong but I spent time looking online on revenge and prank ideas although I knew Id probably never really do anything but it made me feel better to think about it since it is so unfair that this person hurts you and then nothing bad happens to them.