Your hair sounds a lot like mine, although I'd say I'm a 3a. My hair is super fine, but lots of it, curly/frizzy down the sides, and can be almost straight at the back. You're not alone!!!
Sarah.

Based in the UK. 2-something (2b?) hair. Very porous, fine and brittle/fragile

Hair loves: Drip drying, glycerine, shea butter, oils
Hair hates: Plopping, any kind of gel, most conditioners (scalp issues).