Hair loss following childbirth and extreme dieting

It's been 13 years since I had my child, but still

I'm worried because I'm losing too much hair.

After giving birth, I couldn't manage my hair at all and didn't realize it was falling out. One day, when I first went to the hair salon after raising my child, I noticed that some parts were missing. Since then, I have been eating well, but after a sudden weight gain following childbirth, I tried an extremely strict diet to lose the excess fat. Now, every time I wash my hair and comb it, I shed a lot, and the top part looks so thin that it appears very sparse. Even though I finished dieting a long time ago, once the hair started falling out, it hasn't improved even when I eat well.

I've used up all my hair loss shampoo and conditioner, but is there any other way to protect my precious hair? Haha