I am so tired of how my life is going

I (50F) am tired of how my life is going. I feel like my life has amounted to nothing. I have my daughters and love them with all my heart, but it feels like they are the only reason I'm here. I still feel alone. I feel like I will die alone. I have no love life. Every man I've been with has failed me. The man that I truly want in my life is emotionally unavailable and is separated, but he won't take the next step to be with me or be honest about what's going on in his life. I feel like nobody wants me. I feel alone. I don't tell people about how I feel because it's like no one understands how I feel, and I don't want them to worry about me. Some people tell me to start dating, but I enjoy my peace and not having to answer to anybody. However, I do want companionship. Someone I can pick up the phone and do stuff with. I have no social life. All I do is go to work and come home. I feel like no one respects me. Everyone is always so rude to me at work, my teenage daughter, and even random people. I never come on here, and someone suggested I should just write out how I feel. Recently, I had to cut it loose with the man I wanted in my life, and I feel so done with life. My last straw today was when I just wanted to get some breakfast and asked for the menu, and the lady was just so rude to me about it. I just broke down and cried. It feels like nothing in my life has gone my way so far. I never been the woman who gets what she wants in the end. It feels like I do everything for everyone else, my family and my kids, but I'm still always treated with no respect. My mother doesn't even call me and talk to me over a disagreement that happened YEARS ago, and my father passed when I was 24. I just feel like I have no one, and I just feel rejected by everyone right now.