Have you seen a doctor about the microhairs and shedding? Is your diet clean and balanced, anti inflammatory and your weight in the healthy range? There are strong links between type 2 diabetes and various nutrient deficiencies or imbalances, these can easily have a negative effect on skin or hair. Select Vitamins and Minerals in the Management of Diabetes
Other than that be gentle on your hair, be careful with your styling methods, regular up dos can cause a lot of damage as can dry detangling. If possible detangle slowly and gently in sections with a super wide tooth comb perhaps followed by a Tangle Teezer when hair is soaking wet and slathered in loads of a slippy conditioner.
Damaged hair won't grow it will just break off or the rough parts snag on the healthier parts, your prime goal should be hair health and your secondary goal length. It's taken me two years to grow out the worst of my damage when I'd prefer to grow, but honestly it's not worth having a few more inches of horrible straggly rough looking hair. Agree coconut oil is amazing as are hydrolysed protein treatments.
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
Treatments: Komaza protein, Komaza Matani, coconut oil with sugar syrup. Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume
Styler: Umberto Giannini jelly, Boots curl creme, Rockin RInglets
Experimenting with: Mega-Tek, Curl Harmony reviver, Elvive Full Restore 5.