I am curious how you take care of damaged hair.

I want to grow my hair out.
Whenever it reaches about shoulder level, the ends get so damaged that I end up having to cut them.

I've tried treatments and applied oil, but
I don't know why the ends are splitting like this.

At the hair salon, they call it a hot air balloon line.
It’s not easy because my hair gets so frizzy without a curling iron.

I'm curious how everyone takes care of damaged hair.