I climax very fast and i believe it's medical problem?

Address it: Climaxing rapidly is almost never a sign of systemic ill-health. If a little topical anesthetic on your glans doesn't help, your physician can give you a low-dose of a selective serotonin reuptake inhibitor. Better, learn the squeeze e technique and practice it with your partner. It will reprogram you and is a lot of fun. Best wishes.