Hey,
Welcome to RYL :)
I think part of the battle is wanting to stop and it's clear from your post that you do want to stop, so well done. You should also be proud of your efforts to stop self harming by starting to see a therapist and also trying the different techniques.
I too have experienced sexual abuse and as a result, self harmed for a long period of time. I have been lucky in that writing has been helpful for me but also talking to people. Sometimes I do need to rely on medication as well though - I don't know if that is something that would be an option for you or not?
With regards to talking to your therapist, try not to push yourself. If you have only recently started meeting with her then it's understandable you have trouble discussing the abuse. It's a hugely personal issue and you need to feel totally comfortable with the therapist and have a lot of trust placed in them. I'm sure with time though you can get to that point.
This link is for the self harm information package which has loads of information that you might find helpful to have a read through.
If you ever want to chat, feel free to PM me.
Lottie x