Instead of straightening, why don't you try twist outs or braid outs for more "wavy" looking hair? Honestly, I would kill to have 3b hair.
2c-3a - coarse - normal-high porosity - high density - growing out to donate
NP/LP: KMF Whenever Conditioner/ Sevi Pumpkin Seed or Seabuckthorn Berry, YTCucs
RO/LI: Sevi Pumpkin Seed DC / CJ Argan & Olive Oil, KCKT, Komaza Aloe My Hair LI
PRE-POO/DT: Coconut Oil + scalp massage
OIL/STYLER: SM Elixir / KCCC, DC Light Defining Gel
COLOR: henna, amla & indigo
= glycerin in low dews