Marry him or not

I am 32 and my boyfriend just turned 21. I am currently still married to my husband who only does for one of our children and the one he does for he barely does that. We are getting a divorce our relationship was toxic but we had good times. I want to marry my boyfriend I love him so much. And he actually loves both of my boys. My mother in law says she loves him but I think she does to a certain extent.