I think I'm falling out of love with him.

I am lady of 26 yrs,dating a 28 yrs old.we have a 4 yr old girl whom he loves very much ”3yrs he cheated on me with a 16 yrs old and impregnated her.but the girl decided 2 abort. But now this girl has another child and rumour says he the baby father”I’ve confronted him more than once but he denied it period•so now this is affecting our relationship•i think I’m falling out of love with him•i want 2 leave him but I’m worried about our child I don’t think she can survive without him