After he died I found out there was another girl (m25 f29 f29) how to get through this?

I had a long distance connection with a man for almost 2 years and he passed very recently. after he passed I found out there was another girl who he was talking to for months before he started talking to me. both my relationship with him and her relationship with him was filled with ups and downs and he never chose either of us clearly. I believe he died without having made a choice. now he would bring up marriage to both of us (brought it up to me first but I shut it down) and I would refuse without him being stable but she had accepted. he called me the same day he proposed to her. in the end he was too indecisive and she walked away because of it and he ghosted her last message. meanwhile he continued talking to me up until he passed and brought up marriage with me again. I had finally given him an opening for it shortly before he passed while he was still entangled talking about marriage with her and he didn’t take it but once their relationship broke down he brought it up to me again. in the end it seemed like he chose neither of us. I don’t know how to let him go or work through this complicated grief. it’s been really hard for me because I loved him as did she. he did not tell us and led us to believe we were the only ones the whole time. I’ve heard of stories where men can’t choose between two women but usually that doesn’t last two years and usually the women are aware of each other while the man makes the decision. this was way too long and way too involved (he treated us like girlfriends- nicknames, future talk, love and feelings, etc) and he ends up dying. I’m in a turmoil of feelings and I don’t know how to get out. I still love him despite it all and it hurts a lot because he was my first real relationship and we both were very emotionally involved with each other. how do I accept that I don’t know his choice, that he may not have even known and the biggest thing: that he died and I will never get any answers or any more time with him or be able to change anything?