About 3 months ago? my scalp started to itch!

It doesn`t itch all day but about 5-6 times a day. It starts suddenly, and I can`t help but scratch it. Once I scratch it, it gets better.

But today after I scratched my scalp, my fingers had blood and scabs on them

So.. I was considering using the rh-s serum. How fast would the itch go away? Does it take long?

Please tell me how to get better faster.