You are absolutely right. You deserve better than that. Much much better. Don't sell yourself short.
My husband's affair began when I was 37. I wish I had found out then. It would have been difficult, especially with four young kids, but not impossible.
I know he would have honoured his financial support responsibilities, I would have resumed my career and I may have had a chance for happiness. Instead, he stole my happiness and I continued in an unfulfilling marriage for 15 years.
You are young and you sound strong. Your best years are yet to come.
Don't waste them on someone who does not cherish you.
Don't settle for anything less than you deserve.