I just recently started zoloft (sertraline) again and just read about some people having permanent post-ssri sexual dysfunction. is this a documented possibility?

Not common but...: It happens and there is research. It's not common so if the depression is severe and not responsive to talk therapy, it might be a necessary risk. You'd get my approval if the depression is moderate or mild to try good psychotherapy alone and add Rx only if needed. SSRI Persistent sexual dysfunction is a small possibility. http://rxisk.org/post-ssri-sexual-dysfunction-pssd-wikipedia-stumbles/