The person you met probably isn't the real person he is. Alcohol skews everything. Good that he is in rehab. Hopefully he can get healthy and take control back of his life and not be a slave to a bottle.
Your relationship with him was only 5 weeks .. not long at all. Why would you be agreeable to let him be in charge ? He also lives in another country, are you willing to risk moving there? If things don't work out what then? You should not feel like a failure He treated you poorly in only 5 weeks with him. That should tell you something. Usually people are on there best behavior in the begining of a relationship.
There is no telling what kind of person he will be if he does follow through with rehab.. He could be just as controlling and saying hateful things. You deserve better.
If it were me I would just drop the whole mess and move on.
Good luck