My curls are unmanagable & frizzy. No products work on it. What do I do?

 I have thick, coarse hair. The curls are all shapes, straighter on the bottom layer, more coily in the front, but mostly S shaped. It frizzes immediately after being rinsed. The back is always tangled because it's the thickest portion. Oils make my hair dry, leave-in conditioners make it oily and dense, gels/serums & mousses are too light. My hair continues to get bigger as it dries. It forms into a giant, fluffy, tangly triangle, even with products. I've been struggling with my hair for 2 years now, and I'm really sick of it. I want to cut it off, after getting it cut 2-3 inches off my shoulders. (It was shoulder length.) It is not cooperating with anything and I'm really tired of doing it.