The discomfort you are facing might be because of a sensitive skin,thinned out layer of the foreskin on that part you are mentioning ,fungal infection
of a minor intensity or slower pace of tissue regeneration.Whatever it is you can follow the following measures to improve healing rate.
1.apply a mild antibiotic ointment in the night and after you get a tear.Neosporin
ointment ideal if you are not allergic to it.
2.Take one antioxidant with multivitamin
in a pill form.
3.Check for blood sugar -the crack is common in high sugar.
4.Take a tablet of flucanazole 150 mg once in a week after consulting your family doctor.Can give treatment to partner also even if she does not have symptoms.
5.Ejaculate once or twice a week if possible to prevent semen leakage or accumulation of semen to give more vigorous erections at night.
6.eat a healthy food.
7.Consult a pranic healer to take care of your energy field.