Your hair looks lovely
Damage, even a small amount, tends to pull out curl, and from what I gather heat damage is especially bad. A protein treatment might really help, I love curl junkie repair me. Gel can definitely do it, but you have to be pretty adamant about scrunching it, then leave it alone to form a hard cast, then scrunch out the crunch. Mousse is worth a shot too, but for me it's only really curl enhancing if I diffuse dry. Also it's important to get a good moisture balance. You want to get enough moisture for your curls to really plump up, but you also don't want to weigh them down. I have similar hair, I think it's 2b/3a, I used to think it was 2c, but now it looks more like there are just two desperate curl patterns in there. But with a little effort, I can be totally 3a, even a little. 3b.