Female crown hair loss concern ㅠㅠ

Since I was young, I've often been told I have a lot of hair, and when I was a child, I had so much hair that I couldn't even pin on most hairpins.

I thought it would last a lifetime... I didn't know I would lose my hair like this ㅠㅠ

The biggest change was childbirth.. After giving birth, I was really surprised to see so much hair falling out and my crown becoming bald.

Even now, my crown is still empty... I've tried changing my parting, but it seems useless ㅠㅠ

My hair is falling out and growing back so much that I have a lot of fine hair, but only the crown area is noticeably bald...

Should I use a shampoo that is good for hair loss? Is it effective? It seems to be quite expensive too ㅠㅠ