Greetings. The scalp one you mentioned is similar to me, though I just use my nails. I hate uneven bumps on my head. I pick the scabs I have left the previous picking. I mainly pick at clumps of dry skin since I have tried basically everyone to get rid of it. I believe it's mainly caused by stressed, since when school was over, my scalp wasn't dry at all. I feel embarrassed by it too, mainly due to social anxiety though. I feel people judge me when I do this, but I can't stop doing it. The things I have tried for the scalp problem are:
-cut nails with actual nail clipper
-shower more often to reduce dandruff clumps
-wear a hat
-wear gloves

The hat doesn't really work, since I still scratch, but I can't make my scalp bleed this way. The gloves work. The thing that's the best, but doesn't totally fix it is cutting your nails. The longer my nails, the more I pick because I can take more out at a time. With shorter nails, I can't so I don't try ask much because I think there is less there. Anyways, hope this helps [emoji3].