Venting

I just need to get some things off my chest chime in advice feelings what ever idc

Okay so I'll start with I'm 25 with four beautiful kids 8,5,2,6mths I work part time in school full time to become a lpn. For starters I have a mother who uses my kids as some type of bargaining tool. This isn't new to me but I'm tired of it... examples if you don't bring me food I can't keep the kids.... just yesterday I told her I didn't have much gas to take her to the bank and she say well I can't watch your kids remind you I had to go to class and I also pay her to keep them. If it wasn't for me going to school I wouldn't send my kids to her but I don't make enough to pay for childcare I'm just so tired of dealing with this... why do I have to pay you to keep your grandkids knowing that I'm trying to better myself, why do I have to do things for you in order to keep them and if not possible you won't do it smh