Any advise pls

I’m 18M and long story short ive been masterbating for years and years untill I noticed I couldn’t fulfill a full strong erection and be able to keep it, now it’s a weakish one and if I am ever able to get a full one i can see it go down , do I need to see a doctor due to my age or will stoping masterbating cure me

( I am 8 days clean today )