Emotionally abusive(long but please help)

How would you end a three year emotional rollercoaster of a relationship? He is on my last damn nerve with his emotionally abusiveness. I cant take it anymore. I should've left along time ago but the idiot i am, i thought i could change him or he would want to change for himself to better our lives. But here we are, living in my dads house, arguing almost every waking minute, broke because he spends all his money and takes a big chunk of mine and still expects me to get him shit. He doesnt pay rent(30 for Wi-Fi) he put gas in my car last week for the first time in months. I usually have to ask for gas money from my family, and he still expects me to just drop what I'm doing and get him. I really dont know what to do. Ive been crying all night and since i took him to work..Everybody has always told me what a piece of work he is. His own damn parents don't even like him since they saw how he treated me...

To make matters worse, I kissed another guy last night..and I just feel horrible.

I planned on breaking it off today but im afraid he might snap and hit me..

Please help me..

💔