Phimosis?

The person I asked about this, who is qualified to diagnose and treat such a problem (as I am not), said that he'd not heard of any creams or stretching techniques that would be effective unless you are a small child (which I'm assuming you're not). In very young boys, the foreskin can be stretched somewhat if it is not too tight. But he was unfamiliar with any creams, except that he said in the sense of lubrication in terms of lessening discomfort while stretching was going on.

But this person said that if you cannot stretch the foreskin completely over the glans of the penis, you should get it snipped-in other words, be circumcised. He said that it will only get tighter as you get older, and the danger in not doing anything is that this situation could inhibit blood flow or circulation, which could have a devastating effect on the physical manifestation of your manhood. Tight foreskin also increases your chances of developing infections, etc., and at some point it could become stuck and you would require emergency circumcision anyway.

This does sound like something that could be a serious issue. I'm sure you've already googled it, but the internet cannot make a specific or accurate diagnosis on your particular case.

If I were you, I'd see my doctor, and if I didn't have a family doctor, I'd try to get a referral to a urologist. S/he will be the specialist who will most be able to help you.