Should I let it go or continue trying?

My boyfriend and I split due to excessive drinking on his behalf and turning into arguments, everything I say at this point is sensitive I have to walk on eggshells! I have 2 kids and he has 2 kids his kids mother passed away! His kids don’t respect me and their dad doesn’t enforce them to respect me! We split for these reasons!! He now moved in with his sister who he now has to lie too about talking to me! Should I continue to try and work it out or let it go! I’m hoping he can see with us apart how much I really did for our families but it seems the sister is now taking all responsibility once again and taking care of them all!!