I'm in my late 30s, and I've been around the block so I'll share mine. In terms of worst time being broken up with, that was my last ex prior to my wife, and she did a number on me. It was entirely my fault and all of the red flags were there and I ignored them and she's a huge cautionary tale that I won't go into because honestly I don't like thinking about her. I didn't really get a say in the breaking up, and looking back I'm so very glad it happened but it still crushed me emotionally for a long time.
The second, and really the harder of the two, was the hardest thing I've ever done. It was my longest relationship (4 years) up until my now wife (married 3 years, together 7). I met her in my early twenties. When we both graduated our programs, we'd only been together a little over a year and didn't plan on staying together. She wasnt sure where she'd do her master's, I wasn't sure where I'd be working. As luck would have it though, we both ended up in the same place, and stayed together another three years. The last six months or so of that relationship I realized how completely miserable I was with everything but her. I loved her, I still do to this day and always will, but I hated my job. I hated where I lived. I hated being so far from my family and friends. And it got to a point where I needed to tell her and figure out how to move forward. So after a long work trip I spent 5 days with her and told her how I felt and she understood but she loved it where we were and wanted to stay for her PhD, which would be after another year of her current program...six more years. She was happy where she was and she could see I wasn't happy and we talked and thought up scenario after scenario before we came to accept that we needed different things...it fuckin hurt man. We knew it couldn't keep working without someone resenting the other and we realized life was taking us different places. We broke up 2 days in, I spent the rest of the time with her and there were many tears and lots of pain and lots of last moments together that we savored.
It hurt so badly because nobody did anything wrong. We didn't stop loving each other, we didn't stop caring, nobody cheated, we didn't grow apart so much as life pulled us in different directions. That's probably what hurt the most, is how much I/we didn't want to end it, but how we both realized we had to. Life happens and that's okay, but it hurts sometimes. I am happily married now, and she is too and we're good friends now. My wife is my best friend and I can't imagine being with anyone else. I am happy for her and her husband is great and I can see how happy she is. I am not upset with how either of our lives turned out, but I also know there will always be some regret there.
Have you tried having better luck?