Dandruff 😓

I have issues with my hair falling out in small clumps but it goes on all day( I leave hair on chairs, hoodies, my bed even tho floor), dandruff- I’ve used head and shoulders which I know doesn’t work and idk what to do abt it bc it gets really bad especially during the winter

And my hair gets really really oily after washing my hair the day after( I have an issue with washing my hair every time I see dandruff or oily hair and I know that’s bad bc it causes clogged pores and build-up) I need help 😖