First, there are two ways you would get a tight foreskin. One is if you never skinned back.
The other is if you could skin back before, and now it is tight.
If you never skinned back, try pulling your foreskin away from your body, about 15 minutes a day. Then, after a few weeks, insert your little fingers, and gently pull them away from each other. Do this every day for 6-8 weeks. As it opens, use your index fingers and thumb.
If you had been able to skin back fine, and now can't, you very likely have a yeast infection. If this is the case, the yeast is causing scarring. Scar tissue is not as elastic as skin, and over time, you may lose the ability to retract the foreskin. If this is the case, go to the doctor, and get some antifungal cream. Any partner would also have to be treated. Once the yeast clears up, regular stretching, for at least 15 minutes a day, should have you skinning back free and easy in 6-8 weeks.
If you go the 8 weeks, 15 minutes a day, and still can't retract, go back to the doctor, and ask for betamethasone cream. It's a steroid. You apply it to the outside of the foreskin, and it thins the skin a bit. You then stretch in the regular way. Most tight foreskins can be resolved without betamethasone cream, but it is really good for the stubborn cases. You don't need surgery.
Don't stretch when you have an erection. If it starts to go up, wait until it goes down.
There is a slight chance the foreskin will get caught behind the head, and swell up.
It then cuts off the blood supply to the head. If that happens, you have 20 minutes to get to emergency and have the blood supply restored. This is why it is better to stretch without an erection. If it does happen, use olive oil, and squeeze the blood out of your head with your fingers. It is much easier than a trip to emergency.
There is another thing you should know. If someone tried to force your foreskin back before it was ready, there can be tearing, and the foreskin and head can grow together. This is called an adhesion. Just under the piss hole, the frenulum attaches the penis skin under the head. That is normal. Any other place, it is an adhesion. You can sometimes fix them, by greasing up with olive oil, and gently pulling. If you have an adhesion, and try this for a week, and it still does not give, see your doctor. He or she can slice it free with anesthesia.
Then, you apply petroleum jelly, every day until it is healed, to keep the raw parts from being able to heal together again.
About the hypersensitivity...think of how your eyes would feel, if they were closed all of your life, and then you opened them. Light would be blinding, until you adjusted. It is the same way with the nerve messages from your head. It will take a little time, and a little exposure, like a month or so, for you to get used to it. Then, it turns from pain, to ecstasy.
Let us know how it goes, and if there is anything we can do, to help, or to put your mind at ease.
