I need advice over how to grow out my hair and get it to become thicker.

Hair Info: My hair type is probably 3c-4a, it gets wet pretty fast but takes long to dry completely, pretty short, usually never touches my shoulder, hair is very short in the mid back of my head, pretty frizzy, have recently only been doing twists or just natural or buns, and doesn’t get severely tangled but does tangle easily.

Backstory for hair: When I was young, my mother used to detangle my hair and she used to leave chunks of my hair afterwards, this was when I was younger. I usually wore my hair in a bun, which has not been a good thing. Has been straightening prob 10 times maximum over the course of a few years, and blowed out(with that brush thingy???) prob the same amount, has been dyed with hair dye shampoo, black box dye, blue box dye in peekabo parting, box bleached, then dyed again with boue hair dye in the same form(peekabo as well as the bleach). Hair is usually cut by me because I hate struggling with tangles that will cause too much breakage to detangle. 

Products/stuff I use: Right now, I’m using mielle rosemary and mint shampoo, shea moisture black castor oil conditioner, mielle mango and something leave in conditioner, sometimes eco gel, and I wear a cheap Walmart bonnet 
most times💔. Before, I’ve used mielle products, As I am , garnier, that brazilian hair cream that comes in a big ahh bottle, eco, doux, and some more brands/products I don’t exactly remember.

If any more info is needed to figure out something, I’ll provide it. Just, please, help me because I’m kinda tired of having short hair.

How to grow out hair?