irresponsible husband

I have been married for 3 years to my husband and we have 2 children. He also has 2 other children, only one of which he sees. We both work and I also go to school. He makes much more money than I do and most of the time works until dark or later. I ask for a certain amount of money every week for bills and I take the responsibility of making sure theyre paid. As well as his child support payments. He is a self contractor and is supposed to keep all gas and tool receipts as well as getting all his employees info, hours, pay, etc for tax purposes. He never keeps receipts and always forgets to get his employees info (he goes through a lot of them) I tried helping him for about 6 months but he would always forget to give me their hours or wouldnt write them down still would forget receipts, etc. So I thought I would let him use my walmart card to keep up with gas by using iur statements and he would just pay what he used in gas gor the week wevery friday when he got paid. Well he lied about how much he was paying and was using the card for misc. Things and before we knew it, in only 2 or 3 months he gas it maxed out at $4000. He also went behind my back and bought a $700 phone and pays twice the amount he wa paying on my plan and I now have to pay an extra $30 a month for his suspended line. He also always complains that he has to "babysit" his own kids when I pick up extra shifts at work but he usually works late nights leaving me with kids the majority of the time. (Which I dont mind, its just the point) He also spent half our bill money on parts for a boat that isnt even ours 2 weeks ago and when I told him he was irresponsible and I was considering moving out he begged me to let him prove to me he could manage the bills so I said fine I gave him one of the money orders for his child support and told him how to mail it and then gave him $600 for his other child support. Ita been almost 2 weeks and he hasnt mailed the money order and spent the $600 apparently because he only gave me half the money I needed for bills this week and I checked his wallet and he has only $120 in it along with the 1 money order I gave him. He also has fallen asleep multiple times while watching iur children while im at work. He never finishes anything he starts and always yells in front of the kids. Ive gotten to the point where im numb to it all and dont talk much at all to him. I feel like I hate him sometimes and rarely ever want to have sex with him. I have never been in debt and always have my finances in line but im so stressed out abiut money and the debt ive endured since being with him it makes me physically sick. Should I just take my kids and move out with my grandma and hope he changes and hope my feelings come back? Or should I just file for divorce? Im only scared that if I dont take kegal action about our finances im going to get stuck paying that $4000 along with other debt hes caused. Hes already started drinking again. In fact last night he didnt come home until 8am. (He asked me to go iut with him but I dont drink and was tired and honestly didnt want to be around him) He was trashed. And I know he wasnt with a woman hes not a cheater and my friends saw him out with his guys. I feel he will go back to his partying ways and completely omit any responsibility he has with me or the kids