Extremely frizzy hair

I don’t really understand my hair type or what to do with it. So to begin with, I have very thin hair and hair loss so I have a lot of bald spots on my head from an undiagnosed problem, till now no doctor has been able to help me find out why I’ve had hair loss since I was 13, I’m 21 now. So I’m already very insecure about that. Second, my hair type changed, when I was little I had straight hair and as I got older it changed to wavy—> to curly. But it’s more so wavy/straight on top and curly on the bottom.

However, after a day of washing it my hair loses all volume and curly-ness and just turns into either straight/wavy + frizz OR a huge puff ball of frizz with no type of definition in my hair. I live in Florida so immediately stepping outside my hair gets extremely frizzy. I’ve tried using frizz oils and they do nothing for me, plus if I use too much it makes me hair stick together causing me to show my bald spots even more. I hardly have “good hair days” because I don’t have them, my hair is always frizzy with no definition unless I just washed it and I’m inside my house with ac.

I don’t want to use heat because that’s so damaging to my hair and will make it fall out even more, I don’t know what to do honestly or how to control this frizz, any help?