Ultra Thin Hair Tips? 😬😭

I have incredibly thin hair.. I’m talking, stripes constantly. I can wrap one of those little black rubber bands for like styling hair 3 or more times depending on the thickness of it 😭 It’s much thinner up top.. basically if I wear my hair up I have bald strips almost that I can’t really hide unless I pull the hair up and bit to lift it a little. Give the illusion of hair 🙄 or whole bald spots if I don’t brush it into a ponytail.. If I wear it down I have a big bald spot in the back.. it’s unworkable. I’m just ready to have a Brittany Spears moment and shave it all off! 😩 Please help me. I haven’t dyed my hair in over three years, don’t use any heat source on it ( only blow dry if going out, which isn’t often) I use a $10/ bottle shampoo and conditioner for thin hair without all the bad sulfates. I’ve taken vitamins.. 😩😩😩 any good tips or anything?