Give it time.
My was like that too until one day while in the bath tub.
I read at http://www.ksnocirc.org that the foreskin is normally attached or fused to the glans (like the fingernail to the finger), and slowly separates as part of normal development.
my husband had the same thing...but one day during sex it ripped and now it goes down all the way but it was extremly painful for him for like 2 weeks...
I'm 24 now and when I was 18 I had the same problem and then one day I was having sex and it broke. It left like a lil skin on the top but I had that removed. All better now...it didn't hurt me at all when it happened but it freaked me out. Also after it breaks some times it is better to check with your doctor about it getting circumsised because it helps some times.
You should not be worried, but you should bring up the subject agai with your doctor. Or ask your parents about it and maybe see a different doctor. At 17, you should not be having problems exposing the glans penis for urinating and washing. You should be able to talk to your parents about anything and I hope you can.