OP, I think most of us have been in your shoes in some type of way. I know I have. It took me forever to get over my ex. I would constantly fall into his trap of lies. He took me ring shopping.
He told me that he knew I was his future wife.
He said he couldn't live without me.
He said he would never cheat on me or hurt me.
I never got any proof that he did me wrong, but I didn't need proof to know that he wasn't doing right by me, and you really didn't need the proof either. I am a certified witness that if you are willing to let this piece of trash go there is a better man waiting for you! No, all men are not dogs. There are some good men out there! They are not going to be perfect, but you will find someone who is perfect for YOU!
It wasn't too long ago that I was in your shoes (or shoes similar to yours). I literally thought my world was coming to an end when my relationship with my ex started falling apart. I hit some really low days. But I am with a better man now who knows how to treat me and who doesn't play games! I am SO GLAD I finally moved on. It was definitely worth it!