I can't help myself, I'm always cheating and I can't stop.
Why would you want to cheat all the time?
It's just so easy for me to do.
While it is a good thing that you are being honest with yourself, you need to also realize the damage you can do when it comes to cheating. You are really hurting your partner when you decide to cheat on them. If you would rather not be with your partner, a good idea would be to break up.
What type of human would do that? My partner would be alone and heartbroken.
I understand that, but you are already hurting her by cheating. You need to be honest and explained to her what you've been doing. Then you could try to fix a relationship or end it.