Is it normal to want to just have casual sex

Damn! You need a good fucking. Hook up with someone you can trust (no diseases, safe and understands it's NSA).
I've "serviced" a lot of my female friends who have been in the same situation. Sometimes, it made their marriage stronger, other times, they realized (found out) how awesome wild sex is. I'm extremely uninhibited and will do ANYTHING to get a girl to cum. OK, she has to be hot - I can't "do" or "get off" on/with someone I don't think is attractive.
These came to the conclusion, that if they want a satisfying sex life, they had to find someone else. Whether it was "on the side," or just completely leaving the marriage.
Good luck and hope you find some mind blowing orgasms in your future...