I've been through this, too. You're getting lots of great advice, already!
1. Be easy and patient with yourself. There are some great books out there, "the betrayal bond" and "don't call it love". Both deal with sexual compulsion.
2. What has been explained to me is that you have to give up asking yourself why? HE JUST IS and you will never understand it
3. Stop talking about him in terms of "the love of my life" of as having "the greatest sex". Keeping him elevated on some pedestal is not going to help get him off you mind. [given how he treated you, he wasn't great. any person deserves better.]
4. Love does not hurt. You've been through a lot, be easy and patient with yourself most of all.
5. It was about me finding the lesson. With a lot of hard work and patience.....I did. Today, I give gratitude for the struggles that have brought me growth, maturity and resilience. I wish you the best on your journey!!!
OP: I went through something very similar: he cheated on me with dozens of people over years (even in public restrooms while we were at the mall), lied about it, then one day came the shock. I tried to forgive him, then cut him off when he cheated again. Next? Years of therapy for me!
But Kevinap gives some great advice: find the lesson! Why did you get into, and stay in, a situation that was so harmful to you? Once you figure these things out, your life can be fantastically better: you can now form positive relationships that are happy and healthy.
Recovery will take time, be patient.
Stay in therapy and work this stuff out.
Read the Patrick Carnes books that Kevinap suggests.
When you're ready, date again.
After a few years of embracing my recovery, I'm still often shocked to see how things have gone from terrible to wonderful:
My first, disastrous/traumatic relationship forced me to learn better dating skills; now I have a great guy – and even if this new relationship were to go wrong, I can take care of myself, so that I don't stay with someone who treats me poorly (like before).
You'll be fine – just nurture yourself mentally and emotionally. If you embrace your recovery, you'll soon be in better shape than you've ever been.