Hi there, welcome to LHC! I had the exact same problem, my hair was matted and tangled all the time and soooooooooo dry! I never heat styled it, I have virgin hair, I oiled it regularly and trimmed a lot. I have 2a/m hair, too, so we may have experienced the same thing for similar reasons. For me, strangely enough, it was conditioner that did it. I think the build up from the cones in the conditioner, no matter how nice or supposedly "hair friendly" or "detangling" it was, I would ALWAYS end up with crunchy ends and huge dreads after I worked, slept, anything, even if I oiled it and brushed it regularly and babied it a lot!
I heard about water-only washing and at first didn't think it would work for me because I couldn't imagine detangling my hair without conditioner, but after researching it a bit I decided to try it and I am hooked. I don't get matted tangles EVER anymore! It seems as though the conditioner would fix the problem in the short term but the more I used, the more I needed. Now that my hair is full of it's natural oils and sebum it is so soft and silky and healthy even if I have a really rough working day in the garden. It turns out that my hair wasn't actually even that dry, but the product build-up gave the impression that it was.
My routine for the first few months of WO was to put a tiny bit of oil on my fingertips and work out all the big tangles by hand, then comb or brush, and then use a boar-bristle-brush to work the sebum and oil throughout the length of my hair, and rinse with water when needed. Now I don't need the oil anymore for the tangles (sometimes I put essential oils in a rinse for the nice smell) and the sebum has penetrated my whole length and seriously my hair is manageable even after the roughest treatment. Also it is cheaper and I can travel anywhere without worrying about which products to bring, etc. Win!
This may not be the best solution for you but I just thought I would share since we have a similar hair type and experienced similar problems. Good luck!