To the OP,
You do not mention how old you are. However, children of parents will often experience the feeling you describe as a natural progression into being an independent and an adult. Once you are an adult, you may be the person who would otherwise never sustain a friendship with an individual who has the attributes of your mother. It is natural and therefore permissable that you may be questioning the maintenance of this relationship on the scale of psychological pragmatism.
Whilst it would be ideal if the relationship between you and your mother is complementary, the fact that it is not and the resultant stress, on both sides, is not healthy. Continuing this relationship could have negative and irreversible consequences on the both of you, individually. For example, your mother may be more inclined to use to attenuate her feelings of stress; in any event, you are currently vulnerable to your mother's influence. Again, it is natural and pragmatic to experience emotion when there is threat or insecurity.
Together, I imagine that your problems are inherent differences driven by emotion. You may be never able to eliminate the inherent differences but you can eliminate the emotional effects of the situation. And you can only control your side of the deal. It may be best for you to simply accept your mother as she is, whether that means having her in your life or not.
Separation has a negative connotation, but oftentimes it is healthy, an eye opener, establishes firm boundaries, gives people room to change, room to grow, to understand what works/what does not. It gives people time to accept change. Inevitably separation may mean also that you grow further apart. But whatever the outcome of separation, if you are doing it to find peace then it is necessary and optimal. Staying together when you know it is a recipe for (two-way) toxicity is not productive, whichever way you look at it.
For the future, there is no need to commit yourself to lifelong severing of ties. You do not know what the future holds. You may be called to meet again in some necessary capacity. Finding your peace and stability now, before that happens, will make you much better equipped to withstand circumstance in a healthy and productive way.
Good luck with whatever you decide. I hope you stay well. x