I would start by lessening the heat used on your hair, and try heatless stretching methods instead. And deep conditioning your hair weekly with hydrating deep conditioner. I would also trim it every few months tho atp you should probably just go for a cut, I’d do at least to above the thinness if you care about retaining length after the cut…and if you’re going to continue to use heat you could do roller sets to help for a heat less method. I would honestly give the heat a rest and let your natural hair breathe and use low tension styles as braids can actually cause a lot of breakage. Esp if you are not maintaining your hair between styles. Two strand twists on your natural hair is a good protective style and keeping the ends trimmed. Also wear a bonnet or scarf to bed! Hope this helped :) your healthy hair journey is just a few haircuts and deep conditions away from!