I think Sarmas makes a good point but I'd also think of it as she didn't mean anything to you before you started seeing her and you'll survive if she suddenly couldn't work with you. Think about how you would cope if she fell ill or moved away, what supports would you use, how would you fill your time and how would you process that ending.

Ending with her will hurt, that's normal in a caring relationship - there's nothing wrong with you and reflects what she has given you that's filled a need despite the bits that have been damaging. I don't think you'll get to a place where ending doesn't hurt and maybe just accepting that it's hard will help you pull away? I guess the reality is you're hurting already, pulling yourself out may hurt but can it be worse than the repeated hurt you experience in that relationship.

Maybe start reducing sessions - are you still seeing her twice a week? Bring that back to one per week then to once a fortnight and use the time to do something for you. Think about what you can use the extra time for, maybe something that matters to you.