Oh God, save yourself. This sounds like a horrible relationship:
1. He cheats on you online and in real life with escorts
2. He is a meth addict. Google "meth faces" to see the possible future.
3. He is a sex addict. Probably not even a problem considering the points above.

I personally would end a relationship just for cheating. I wouldn't be able to live with a person who physically loved somebody other than me while we were together. Or did you sign up for an open relationship?

If you are thinking of staying in this relationship, can you give examples of nice things in your relationship?