i have to agree. this girl is someone who never deserved your love, affection or your attention. especially if she cheated on you and lied as well as gave you no attention in your times you needed her.

it was good you followed your instincts no matter how hard it was for you to do so.

Think of this as a time to spend taking care of yourself and finding who you are as a person.
none of what happened was your fault. You knew when it was time. Again, spend this taking care of yourself and spending time with supporting friends. things will improver.