Foreskin not retracting all of a sudden.

I had gotten some kind of infection due to which I was I was sick for 1-2 days, around the same time or after that I noticed heavy ulcers in my mouth, throat, gum areas, nothing on the body only my mouth, oral infection, some thought it was Chicken pox or something similar that appeared only inside my mouth, I did notice some pock marks on my left foot but those same things were not present anywhere else on my body I took some medication and the oral problem has subsided to a great extent but now all of a sudden I notice that I can no longer pull back my foreskin at all, earlier it used to retract fully with ease, but now it doesn't retract even 10%, also there is some white sticky stuff all over the penile head, first time I am noticing them, never had them before, I was able to clean them by forcing the foreskin back but now it causes too much pain to pull back foreskin and the white stuff has also come back, I think skin has cracked and is dry Please advice I am really worried