Ok this dosent make sense to me really?

husband told me that he got another girl prego, 3 years after we had alrady been together he decides to tell me this....we live in fla and she is in TX well i didnt catch her name....or anything...well now he is saying ohhh its not tru and eerytime i ask about it he is like oh well i lied...whatever im not dumb he thinks i am so i dumped him next step divorce...we already have a 4 year old suppoivly i heard from the great vine he cheated on me soon after our daughter was born, while i was in the hospital having our daughter he was in mexico with his father...they are truck drivers...and supposivly their truck broke down so they went over to mexico...WTF well i know he did some raunchy crap over there...does anyone know how the heck i would even go about getting him to admit and tell me the girls name so i can maybe have proof when it does come down to court,,,?? and also he has cheatd on me many times i just know it i would be stupid to think other wise...does anyone know what really goes on down there in mexico with them girls in bars?...i heard things i just dont know im not talking cancoon im talking straight up mexico no americans around...he just wont come off of the cheating thing...he has been a horrible father and husband he is never there for us and always leaving to go on the road...i now live with my mother and am about to go to collage for my dental hygene degree...thank god i need to move on for myself and my daughter. But i just dont know how to get him to come clean///any advice????