I joined a prestigious university by cheating and my life has never been worse.
What made you cheat?
I was so angry with myself for not getting into the better university.
If there is nothing you can do about the cheating in the past, let it go. Forgive yourself. It will do no one any good to berate yourself.
I'm going to try to get rid of guilt somehow. Once I do, I'll be okay.
You could confess if you truly feel guilty. I wouldn't recommend jeopardizing your education, but maybe you could confess to a therapist or a priest, or someone else who cannot tell other people what you did. That way you can get it off your chest.