Thanks for your query.Based on the facts that you have posted it appears that you have crawling sensation in your penis. You have done almost all investigations which turned out negative for infection.
This could be due to diabetes
which is many a times presenting symptom of diabetes .
Please get your blood sugar levels on empty stomach and 2 hours after lunch done to rule out diabetes.
Ensure to drink more water soas to keep your urine dilute and free from crystals.