Lost my fiance and I cannot cope

I desperately need some help. Two weeks ago my fiance killed himself. He was struggling due to some life events and I didn't know how to deal with it and neither did he. I went to visit my sister for a month (who never like him much) and she told me to stay with her for longer because he was unstable and may hurt me. He had never laid a finger on me before but I was stressed and exhausted and my sister said his depression was exaggerated. She said his suicidal feelings were tools to control me because he had been telling me for a few weeks that he was suicidal and didn't know how to get help. She said if he was really suicidal he would have acted by now. He asked me to come home and told me he was having really bad thoughts of harming himself. He had never had a problem with being on his own before so i was scared for his safety and I packed my things and was ready to head home but my sister convinced me he was manipulating and controlling me by saying he was suicidal. She was really convincing and I told my fiance I needed space and he needed to deal with it on his own tonight. He begged me for help and i told him he was being emotionally abusive. My sister turned off my phone and we watched a movie and went to bed. When I turned my phone back on the next day I had missed calls from him in the early hours of the morning. I tried to call him back but I had no reply and my sister said to give him space so I did. His mum called me in a wreck that night saying he was missing so I went back home. He wasn't there but all of his stuff was like his wallet and phone. The next day they found him. Since then I found out that he went to the hospital that night but they turned him away. He tried to call me and his mother, father and two of his best friends but no one answered.

I feel empty. I feel lost. He is gone forever. I was struggling with his mental health, he had lots of trauma that was showing itself recently and I wasn't very good at dealing with it or him. But if I had known he was going to kill himself I would have been there for him every second without fail. He was the kindest person I've ever met. He never hurt a soul in his life. He was there for everyone and I wasn't there for him when I needed it. No matter what my friends and family are telling me, I know I could have saved his life. I don't know what to do. I cannot move past this. I cannot face his family or friends. I cannot face myself.