Engaged / cheated on / long distance

My fiancé recently came out that he is bisexual. A month later, on my birthday he received positive results for Syphilis and admitted that he had sex with another man twice. We've been together for 8 years. I said I would try to work on the relationship if we went to couples counseling. We are long distance and we don't have plans to close the gap. I have little hope and wish this never happened. At the same time I feel desperate. I want him to make things right and I want to know I can trust him. I also really want to start a family. I feel like at my age (33) the biological clock is getting the best of me. Any advise and words of wisdom are welcomed