Hair issue

I was doing so well w my all natural hair routine. No flat heat for 2 years. But last month I was I needed a hair cut and didn’t feel like doing it my self anymore so I went to the salon. Now i noticed my hair is all different lengths. Broken and damaged

I think it was my detangling it w conditioner cus I didn’t have the wide toothed comb in the shower.

I think I should just cut it shoulder length so it can grow out. I also ran out of my biotin vitamins.

Can stopping hair vitamins make hair break off ? What’s something I can do to help w this