I agree. You need to show your husband yalls budget, its not really feasible. His kids are taken care of but they need to see yall make correct choices about money so that they will when they are adults.
Also, you mentioned typing on your phone, so you have smartphones..that opens up a few options. You could use your phone as a hotspot. $20 a month and cancel cable/house internet. Or you could get rid of your phone, just get a pay as you go one. For years we didn't have cells at all, then for a few years we only had one.