What would you do?

I have been married for 4 1/2 years. We've been together in total for 6. He has changed a lot since we got married. Before he was very concerned about my feelings, would talk to me, etc. Now, he won't talk and if he does he is hateful. He downplays my feelings and tells me to "get over" things. Always puts himself first, and everything is at HIS convenience. He's pretty well isolated me from friends and family and doesn't spend time with my family like he should. He plays video games all the time, his phone is password protected and every time I ask if I can use his phone (for internet if my data is used up, usually) he won't give me his password and he like checks his phone before hand or just won't let me use it. He never apologizes for things he does or how he treats me, but turns it around on me, such as "I'm sorry YOU feel that way" or "I'm sorry you THINK I'm doing that". He is very insincere about things like that. I try to talk to him and he yells at me if I happen to interrupt him. I'm not sure what to do. I love him, and married him and said for better or for worse. But I don't know how or if I can deal with this for 50+ years, because according to my grandma it will never get better. What would you do?