16 and not getting hard enough?

ok so before 2 months i had "sex" for the first time..i've put it in quotes because it was unfinished..we were in the beach and it was soo cold and i had no clothes..when we were indoors i was really hard..but when we were outdooors and i got in her after a while i lost my hardness..and then i couldnt get hard enough to go back in..

after that..now even when i masturbate i cant get hard enough..why is that
whats wrong with me..i used to get hard..
i get hard now but not as hard as i used to.

i get woodys sometimes in the mornings tho