H.K.
Get a copper IUD in place ASAP...it is simple and you cant get pregnant for 10 years, unless you have it removed.
Second, it takes TWO to make a baby...he needs to grow up and deal with it. You need to tell him how to feel and ask him to help you with the kids. You need to tell him that it is not right that he gets to sleep in, then go to the gym and shirk his parenting duties. Stick up for yourself (you are teaching your kids that is it OK for you to be treated like a second class citizen). and it is NOT OK for him to say curse words to or in front of the kids. NOT OK. If he didnt want kids he should have used protection or he should have had a vasectomy...too late now.
I dont envy you. Stick up for yourself and show personal integrity... you deserve to be treated like the mother of his children not an unpaid nanny with sex benefits.
Good luck to you