Dating in my 50's

I have just entered the dating world a couple of years ago after being married for 18 years. Wow!! It has been eye opening. The dating sites and online insta situations. I met a wonderful man and we are engaged. Recently I started to have some physical symptoms similar to having a UTI. It cleared up on its own but it was a concern for me bc I have never been std tested. My new partner has never been married and only had 1 long term relationship. Through conversation I realized he had a link to someone I know is a sex worker. I asked if they had had a relationship the past. He admitted that he had sex with her once. He says with a condom. He did not know she was a sex worker. She is on Insta with 8000 followers - mostly men. Half naked picsI told him that he was single and he was free and that I wasn't judging him but that he needed to get an std test. He has stonewalled me and is not communicating with me, not returning texts. He does this a lot when we need to have an adult conversation. I feel like I get ignored and stonewalled. He withdraws all warmth. Stops calling, texting. It leaves me feeling disrespected, punished and unvalidated. It also leaves me feeling like I am not allowed to have difficult conversations bc he will shut down. How do I move forward in a relationship that encourages vulnerability, transparency and growth with this person I love very much. It feels to me like emotional abuse.