First and foremost: if you're not playing professionally, then you don't need to "fully commit" and your body's natural fear of becoming injured is a great thing to pay attention to. this will become more valuable as you get older and stop healing as easily.

Moving on:

In highschool I (mostly gently) dragged my fingernails on brick/drywall as I walked the hallways to desensitize myself from the sensation & sounds. Chalkboard noises don't really mess with me anymore either.

Likewise, if you place the backs of the forearms on the edge of a table, and shift the arm around you get a pretty good grinding/crunching sensation that's unsettling. I put a good deal of effort into getting over that.

As part of karate instruction, we used Makiwora Boards. You can DIY this very easily, and I recommend it. After you're done ripping up the skin on your striking surfaces, you can soak in salt+vinegar.

Also, in karate, we practiced barefoot on hot concrete for the part of the year when that was possible.