I'm sorry for your suffering.
If you are still living in the abusive situation, can you find other better living arrangements?
Try making a list of things that make you happy.
And do those things.
You need to find ways to distract yourself from obsessive overthinking. You are clearly a highly intelligent person, but overthinking could be your Achilles heel.
And try grounding exercises ... concentrate on smelling a nice scent, close your eyes and identify a sound... look at an object and describe it with 3 qualities eg. a light on the ceiling (round, bright, has a warm glow).
I hope that helps you.
Do you have a psychologist you can talk to? It would be good if you do.