Are you based in the US?. I ask only as you use the word mom repeatedly.
Now you know exactly why he cannot stand on his own two feet; his mother will never allow it. She is treating her son like her surrogate husband. His mother has groomed her son to believe that he is responsible for her happiness and unhappiness. She has driven this home over and over again as he is growing up. Mom will treat her son more like a husband than a son, expecting him to take care of her above all others. Her goal isn't to make him self sufficient. It is for him to turn to her for everything, do everything for her and be number one in her life. No one is allowed to be more important to him than her, certainly not a woman.
You and he are therefore most unlikely to ever move in together and besides which a few months in is far too early to be thinking about that.
You need to read up on and a lot more about familial enmeshment because this is what you are up against regarding him. Honestly I would walk away now from both him and his abusive dysfunctional mother in tow. Both are overtly involved in each other's lives.
He is enmeshed with his mother both financially and emotionally since childhood and their unhealthy bond will not be broken easily if at all. He cannot make decisions on his own without her approval. Furthermore such people do feel guilty and or ashamed if they do not comply with their families wishes. He will have to put in the hard work through therapy in order to overcome their enmeshment and that could take years. And there is no guarantee he'd ever go into therapy.
You will just continue to be further disappointed and or hurt by him if you remain with him. He is far more afraid of his mother and will always seek her approval which she will never give him. Your love is not enough and this cannot be fixed. Do not waste years trying to be some sort of rescuer or saviour here to him because neither approach works.
Where are your parents here; how supportive are they?. You need to rebuild your life without him in it.