I’m about to just shave it off

Hey everyone 💖
So I have straight-ish, wavy-ish hair, it’s not curly (although when I was a kid, it was literal coil curls. those curls disappeared as I aged unfortunately). My hair is ALWAYS frizzy, and it doesn’t matter how frequently I go in for a hair trim, my ends are drying out and becoming brittle instantly. I hardly ever put heat on my hair, but even when I do try to style my hair, I find it hard to feel pretty between the brittle, dry looking ends that never style properly and the frizziness.

PLEASE, like genuinely PLEASEEEE help me 😭😭 what shampoos, conditioners, and other products would help fix this? I just want healthy shiny hair