Try using some petroleum jelly to lubricate under your foreskin. Gently pull it down a little at a time, not all at once. This foreskin stretching may take several days to see complete results.
A visit to the doctors would help, they can do a pretty simple procedure to relieve the tightness.
Tight foreskin is a condition, not a disease. Every male starts life with a tight, non-retractable foreskin. Some get looser automatically and some need a little help.
The foreskin is supposed to be tight and non-retractable in childhood so that it provides protection, but it is supposed to retract and glide back and forth in adulthood. Teens are in transition between childhood and adulthood so frequently the foreskin is still non-retractable.
It is not necessary to have a foreskin that will retract. Some men live their entire lives with a non-retractable foreskin. They can masturbate, have penetrative sex, get married, and father children with a foreskin that does not retract.
You may clean non-retractile foreskin with a rubber-bulb ear syringe. Just fill the syringe with lukewarm water and squirt it into the foreskin.
It is easy to make your foreskin wider and looser by manual stretching.
Almost all boys are born with a foreskin that does not retract. This is normal. It takes years for the ability to retract to develop. About ½ of boys have a retractable foreskin by 10.4 years of age. Many adolescents still have foreskins that have tips that are too narrow to pass back over the penis head. These foreskins may be gently stretched over a period of time to cause them to widen. In most cases the foreskin becomes retractable by age eighteen.
When your penis is erect, gently pull your foreskin back against the head of the penis. As the head attempts to pass through the foreskin it will stretch the skin a little. Do this several times every day and in a few weeks or months your foreskin will widen and you will be able to retract your foreskin. Do NOT force retraction. Do NOT cause yourself pain.
It works by tissue expansion. Stretching skin induces “mitosis” which is a word that means “division of cells”. New skin cells are formed and the skin expands but it takes some time. The increase in size is permanent. Be patient and give mitosis time to work.
The important thing is to put the skin under tension several times every day so that it will grow wider.
Betamethasone valerate topical steroid ointment, which is available by prescription. may help, but it won’t work by itself. Manual stretching is still required.
With regard to masturbating, when you are masturbating, practice pulling your foreskin back until you feel tightness. That will mean that your foreskin is stretching. But do not cause yourself pain for force retraction.