I really doubt it's the cowashing. I would guess it is due to hormonal changes or simply getting older. My hair started thinning in my late 20's, early 30's. and I wasn't CG. your hair and skin changes throughout your life.
2C/ Coarse/ Normal porosity/ SW Florida/ Salt & Pepper
Cleanse: CJ Daily Fix, JC Cleansing Cream, TJ Tea Tree Condish
Condish: JC Too Shea, CJ Curl Rehab (both as RO & LI)
Stylers: UFD CM, CJ PP, JC Spiralicious, Darcy's Cream Gel & Cocoa bean whip