When you say it doesn't accept product, what do you mean? Have you messed around with a lot of different ways, ie, soaking wet, damp, changing the types f products you use?
As for not accepting treatments, lots of hair doesn't like oil so that doesn't surprise me. I can only use a few drops of a handful of oils- my hair rejects most of them.
And like someone said earlier, I see results you're going to have to really use a routine repeatedly. I didn't notice a difference until I had been conditioning almost daily and deep conditioning twice a week for about a month. Then my hair calmed down.
No matter what your hair type, your current routine just doesn't sound like its getting enough (or any) moisture. It's getting protein, but not good moisture. Even if your hair isn't protein sensitive, without a good moisture balance, it's going to eventually build up and make your hair a little angry.
Curly work in progress
2C with some 3A if all the stars align
Low porosity, medium to low density and fine
No sulfates since 2009
CG since 2013

In my stash:
Shampoos and conditioners- Tresemme Naturals Low Poo, Tresemme Naturals Moisturizing Aloe, Suave Naturals Coconut
Leave Ins- Kinky Curly Knot Today
Stylers- KCCC, AG Recoil, KY Lubricant (yup), SM Curl Milk
Gels- Ecostyler, Biosilk RHG
Mousse- Devacurl Uplifting Foam, Suave Captivating Curls