Am I doing anything wrong?

Ok this is gunna be long so only read if you dont mind reading long stuff

I wash my hair every other day Because it gets very greasy and I like for it to you know be clean and nice and stuff Like seriously it gets so annoying because I would have washed it

Then like the next day it becomes greasy like I havent washed it for weeks But I cant wash it every day because my hair is also quite thin and I dont want to lose any more hair than I already have So I wash it every other day and I condition it like twice a week

But I dont know why my hair is so thin Like I spent 2months in hospital And was on medication and had loads of scans and stuff with very little radiation

That was around 6 months ago And my hair is just getting thinner Even tho im off medication and having no more scans

Im eating all the right foods Having loads of protein Omega 3 Plenty of water All the stuff that should make my hair nice and healthy

Can anyone tell me if im doing anything wrong here? And am I washing my hair often? Is there a special kind of shampoo I could use? Btw im using dove at the moment I tried loreal elvive for greasy hair shampoo and it just took out more hair and it became even thinner

Help I just want nice hair!! =[