what to do situation

so long story short my daughter's dad and I had been together for 7 years up until last year, We haven't been together for a year but have had some very passionate sex and reconnecting he has had a relationship with a so called ex sister in law of mine and has been with a couple other chicks, while me on the other hand have been intament with someone, I didn't know how to tell him so he's not happy about how he found out (I was single at the time) what do I do keep fighting even though he says he can't love me again or walk away I love this man with everything I am I'd give my life for him