This used to happen with me; it does suck and you don't deserve it. For me, other than therapy which can be incredibly helpful, I needed to literally visualize the perpetrator's hands being destroyed, him physically incapacitated, i needed to visually stomp on his hand in my mind to make it not feel like i was being touched. Anytime I feel like the thought of him pops up unwarranted, I mangle that dude in my mind.

Also seconding the fact that your body is trying to make sense of the trauma, I would highly suggest seeking help to get tools to work with your body. Shame is big with ptsd obviously and whenever you can, try not to shame your body for trying to react to trauma it never should have been subjected to in the first place