This is something I have struggled with, as you are now. I will give you my 2 cents.

My mother, like yours was the same. Controlling, in the eyes of best intention and care, but also very very critical, so she did not lure me in to live with her until I was 40 (something she would have wanted). When the time came to go to University she did not allow me to go to a university in another country. She would not speak the language there and would not be able to take care of me. That was almost like suicide for me, because like you i knew that she would come round to feed me, get copies of keys to this house, since my parents were paying for my education (no loan was possible where i come from). And she had made it very clear that if she pays for it, it's hers. I still wanted an education so that was the only way. I went to my father crying, who was usually taking her side and hiding behind her skirts, and in a panic attack I told him that i needed to go abroad or I would die. I did not expect it to work but it did. I went abroad and was free of her control. I did not even have a cellphone the first few months so she couldn't reach me (she got cancer which she survived but that's not my fault, it was either her or me). Funnily enough my sister stayed in the country and my mother did to her all the things I feared she would do to me (had her own keys, went in and out as pleased, controlled even what curtains would go up etc).

But the funny thing was that even though I was in a different timezone, completely free and away, I was not free at all. I had actually internalized my mother, as all children do too and I gave up my country, my friends, my warm climate, everything that was familiar to me to escape someone I actually took with me. To be free of mothers like ours, therapy is needed, not physical distance. The distance needed is mental and emotional. They could die and still live within us. That's what your priority should be. To get rid of her inside. If you do that, even living in the same house as her won't bother you (but I still haven't done that).