17 years old, very sudden erectile dysfunction

I'm really confused, just this one day I noticed I didn't wanna wank(usually do that everyday) then I also noticed I didn't get any boners on my school day. And that is just really weird because I usually have like 20 boners through-out the day which are really strong. Now somedays past and I don't get "random" boners in school and I wake up flaccid for the last two days -- and my boners are pretty soft, like a shadow of the old boners I had, a joke compared to them. I use to be turned on 24/7, I had boners like every hour and they lasted like 10min at least and like 30mins or more at most. Now I just feel impotent because I have these shitty boners that are soft and go away in few minutes.

I really don't understand what is going on, just all of a sudden this happens. Is there an explanation? I don't think it's psychological(though I do have some stress about A-levels etc) but then I should be able to have boners nighttime but I wake up flaccid so its gotta be physical.

What is happening? Please somebody enlighten me, this thing is killing me. Am I going to be like this from now on? Will I ever get those strong good boners back? Will I just be semi-impotent from now on?

I use to wank once a day and I wanked 1-2 hours before cumming. Did that for 1-3 years now. Could it be my penis is just tired and recovering(thats what I hope but im afraid its something more serious:(( )

Anybody, please help me