I haven't heard of the GFTN product you used but if you have fine hair the oils probably didn't help.
Second the Sallys idea. You can get a product called Neutral Protein filler (I think that's the name) and add a few drops to your rinse out conditioner.
Or you could just PM IAgirl here on the forum. She's my go to person for many questions!
Coarse texture, normal-high porosity, normal elasticity (Komaza Care), very weak waves
shampoo: Redken Fresh Curls
rinse out: Elucence, CJ Curl Rehab
leave-in: SM Milk, Oyin Hair Dew
jellies/creams: UFD's CM, CJ CCCC
gels: CJ CQ, BRHG, CJ PP