So my hair used to be really curly, I don’t know which structure i could call it though

(Half my make up melted off here dont mind)

But throughout time my hair started to fall out so much! And my curls have loosened up too, its more wavy-ish now and I have no idea since I straighten it around 2 times a month and it has been thinned out so much too

Any idea how I can get my hair curly again like it used to be in the first place and any idea how to take care of it and how to make them less frizzy/pop out more?