Had cellulitis 6/1, treated 1g rocephin, 10days bactrim ds 2 pills bid. on 7/13, i learned i had gonorrhea, sex 13days prior, did he give gonorrhea?

Probably yes: You can be 100% certain you did not have your gonorrhea when you were treated with ceftriaxone (Rocephin) and bactrum; that treatment for sure would have cured gonorrhea. Therefore, you had to catch it sometime later. If your only partner or exposure since then was the one 7/13, that's when you caught it. That partner needs exam, testing, and treatment for gonorrhea.