Desensitized after great sex??

My boyfriend and I had GREAT sex this weekend(it wasn't the first time or anything) a couple times but now I can't masturbate-it's almost like I'm desensitized.. And this is 5 days after we were intimate. 
I try to touch myself but I just can't feel much all of a sudden, or I can never make myself cum. And it used to be easy before. 
Has this happened to anyone and will I ever go back to normal? 😞