Since Buspar has been shown to be basically useless, you more than likely had a placebo effect. Not definitely, there's no definitely in this world of crazy meds, but let's assume you did. That means you healed yourself, essentially. PTSD had good therapeutic treatments short of medication, and no medication can cure it. So, cure yourself of it again!
Buspar was my savior. I was back to completely normal basically after suffering from PTSD for years. I've had to go off of it due to pregnancy and now breastfeeding and am nearly crippled with anxiety symptoms again. I vowed to myself to breastfeed for a year before going back on buspar.