I have the greasiest hair ever, is there anything i can do about it?

I used to wash my hair every day for years, now that i heard its not healthy i try to keep it 1 or 2 days more before washing it, but the last few days it gets greasy even before being fully dried and it seems to be falling out a bit... what type of doctor should i meet or what can i use to fix it? (i live in Colombia so not every shampoo will be available here)