Foreskin not retractable...why?

I'm 27 and i've never had my foreskin retractable ever...is this normal...i used to have a normal till 25 years...with the foreskin covering the head...now i cant mentally stimulate an ...i have to shag up and get erect but it doesn't last long...i can still com though...i dont want to see a doc...recently i have been trying to pull the skin back when i shower...its filled with nerves...i cant even see the head of my ....i am not married but will soon get married...will i be able to satisfy my girl by stroking up an and coming inside her....i need some good easily practicable advice....not to see a doc...not cicision...anything else?