You are not living for them. You have your own life and your own set of problems to handle. I don’t know how it feels when SILs says things like that but I can guarantee that they themselves would not be able to manage even a single with work & baby together. If they were that much capable they would be praising you and encouraging you. Listen from one ear and out from another.
It’s nice that your husband helps you out. I think you are extremely stressed out. Can’t u take 2-3 days off from work , just relax , spend time in your home with your baby and your husband. I believe that it will help you in getting rid of some stress.