Have you tried putting padding on the crib sides, so that she can rock without hurting her head? Rocking is quite soothing, and sometimes people will do so without even thinking about the fact they they're doing so. That might be causing more issues with slamming her head into the bars on the crib.

Are there other things you know sooth her? Is there a way she can rock without it being in the crib? I know personally certain textures are problematic and others are soothing, can there be things in her crib that help? Can you check for changes that have been made recently when she's been hurting herself more?

As someone hypersensitive and seeking, we need ways to regulate ourselves with more input that is also controlled and the correct input. As we overreact to everything, yet need more anyways, we need a way to cope with the difference. Watch how she reacts outside of her crib as well as in it, and give her what you can safely for you helping her regulate and you giving her ways to rock and such safely.