Looking for perspective/ advice

Hello. I’m new to this site and I have been struggling with my adoption discovery. I hoping to gain some outside perspective and advice on contacting my adult half-siblings. I was born on 1978 and my mom and day were 15 and 17 at the time. They divorced when I was 11. My dad remarried and in July of 2017, my dad’s estranged wife sent me a text telling me he wasn’t my biological dad. She did it out of spite because she was angry at him. My mom was very ill at the time. after initially talking to my parents about it I was given some basic info on the Bdad. My mom has his phone number as they had been in sporadic contact over the years. She also had a picture of his 3 children, 2 of which are in their early 30s. The third child is only 9 and from a different marriage. (Side note, my dad knew my mom was pregnant with someone else’s child. He chose to marry her and take care of us. His family was fully on board and his parents were my whole world growing up.) I was not ready to reach out to him but my mom did call to let him know I had found out about him. He asked her to “give him some time” to deal with it. Then my mom passed away in October of 2017. He did not reach out at the time of her death. I spoke with his best friend, who was also friends with my mom. He reiterated that bdad needed some time. Completely fine by me. I was in no rush but I did feel like it was strange he didn’t reach out when she passed away. 1 year after I found out (July 2018) I reached out to him. He didn’t bother to respond. In January 2019, I reached out again to ask him if he could please just give me some basic biological/ genetic info that I may need to know for myself and my kids. Still no response. Several months ago, I reached out again to his best friend to ask if my 2 adult half-siblings Mom was aware of my existence. I told him I planned to reach out to her and ask her permission to contact them. I was told that bdad had relayed to him that now wasn’t the time because my half siblings mom was sick. So now here I am. I want to reach out to my adult half siblings. He has had 2 1/2 years to let them know about me and has chosen to blow me off. Repeatedly. I’m just torn. I want to be there for them on one hand but on the other hand I don’t want to add to their hard time. What if I wait and they wonder why I waited so long? Thank you for reading!