I can only retract my foreskin to mid head level of my penis when im hard. is this condition phimosis? is my current condition bad enough to consult a doctor? what are the health risks of unclean smegma under foreskin?

By definition if you cannot retract your foreskin at your age, you have phimosis. Keeping the exposed area clean & applying a mild steroid cream & gently tugging the foreskin back can gradually end the condition. If you experience pain, irritation, discharge a visit to a doc may be needed. Sometimes a small incision can reduce the tight adherence enough to help resolve it.

Smegma under foreskin should be removed gently with soap and water if you can retract fully when not erect. Inability to completely retract is Phimosis. You can either gradually pull foreskin back, little bit more each day till it gradually becomes supple and retracts completely and freely. Remember to bring it back forward after doing this. Other choice is circumcision.

Do not force the foreskin back. Do consult a doctor to ascertain if surgical or other treatment is warranted. As you described, you would not be able to cleanse the head properly. Get HPV vaccine.