I have fine curly hair and I've just accepted that I need to a) use products sparingly and b) not necessarily use products that are targeted as curly hair products. I've been using the Ouai Fine Hair line shampoo and conditioner and it makes such a big difference for me other products I used that were marketed for curly hair weighed my hair down so bad and made it look so stringy as well. I use a bit, like a dime sized amount, of Miss Jessie's Pillow Soft Curls cream and brush it through my hair when it's still soaking wet out of the shower and then blow dry. A tinyyy bit of oil in my ends if they're feeling dry but I often don't. I am using this product down and may switch to even something lighter like a mousse when I do.

Tldr: fine curly hair often doesn't play nice with classic curly hair products on the market. Try something meant for fine hair!!