Do you think it's okay to get back together with my mentally abusive boyfriend?
Why do you want to get back together with him?
I'm hoping that he changed for the better, but it could be possible he changed to be even worse.
Since your ex-boyfriend has a history of abuse, you should be really careful before deciding to get back together with him. Being with an abusive partner will lead to suffering and significant psychological problems later and should be avoided.
I think my ex is going to change for the better.
You should check to ensure that your ex has really changed for the better rather than just covering up his old ways. Don't feel like you are trapped into this relationship as if there is no one else out there for you.