SP- I feel I helped him get married to someone else

I honestly believed we were meant to be, that the feelings were mutual, that he cared. I believed and affirmed it was “done” and we’d reconnect any day, that we were perfect for each other, that we were to get married, live in the countryside, have children, dogs, the full thing. I used 2 very specific vivid visualisations throughout the past two years, I felt so happy in those moments, it felt real. Found out he married someone he met right after me, I had no idea she existed. Now they have the house, the countryside, the dogs, the children. It doesn’t make sense, I actually cannot believe how it happened. Any advice?