Leaving my fiancé?

So I’m a 22 year old mother of two! My youngest is 8 months and my oldest is 5 years old. I’ve busted my ass the past 5 years and had an amazing job but gave it up to raise our youngest. We knew it would be hard but decided it was cheaper than day care :(. Well I found that I love medicine and have started college!! I’m doing really well and have a 4.0. I’m hoping to become a doctor. My fiancé and I have decided to move in with my dad as he has a huge house and it would save us a ton of money. He’s charging us $300 plus electric. Not bad. I am now trying to find a weekend job just to have money to afford some bills but due to raising the kids and school, the weekend is the only time I can work. My fiancé works a normal job and also runs his own business. I talked to him last night and we had agreed we would split the $300 rent but I asked him if he could please pay the electric because there’s no way I can afford to split it. He freaking said “you better find away because it’s not my responsibility to pay that. And if you are late I’m gonna make sure you pay every late fee”. I tried to reason with him telling him you know I’m in school and taking car of the kids but he doesn’t care. He said I’m trying to “use” him. I’m currently at my parents house visiting so we were on the phone when we had this conversation. He hung up on me and turned his phone off for the rest of the night. I told him I’m done. He’s completely unwilling to help me and he would rather me give up college than pay the electric bill. He asked me why I can’t make my parents pay my half. He has zero understanding of what it means to be a team and he doesn’t want to be. And turning his phone off all night put me over the edge. We also just recently had a problem with him going to our newly single female neighbors house and hiding it from me until her ex husband threatened to kick his ass because he thought they were sleeping together and then the truth came out that he had went to her house a few times but swears to this day that he never did anything. We also had a problem of him lying to his parents telling them that “I am forcing him to work overtime because I don’t want a job”. Even though he admitted to lying I no longer have a relationship with them because of his lies. I’m really fed up with being with him. Am I being ridiculous? Would you end an engagement over this?