Hello Claire: I noticed this is your first post here on PC. So... welcome to PsychCentral! I hope you find PC to be of benefit.

I'm sorry you are struggling with all of this. I'm not a mental health professional. And I don't feel qualified to suggest anything with regard to what this is all about. From my perspective, I really think this is something you need to be talking through, at-length & in-depth, with a psychologist or mental health therapist.

There is a forum, here on PC, dedicated to the subject of self-injury. And although from what you wrote, it sounds as though you're not self-injuring you're imagining what it would be like to be harmed, perhaps the self-injury forum may still be of interest. Here's a link:

https://forums.psychcentral.com/self-injury/

And then, since you mentioned you're wheelchair bound, the health support forum may also be one to take a look at:

https://forums.psychcentral.com/health-support/

Here are links to 2 "Ask the Therapist" articles, from PsychCentral's archives, where the writer asked about having thoughts of wanting to be hurt. Perhaps the answers the therapists gave will help to provide you with some insight into what you are experiencing:

I want to be hurt | Ask the Therapist

Thoughts of Wanting to Get Hurt | Ask the Therapist

My best wishes to you...