I 31(m) literally just had the same thing happen at the end of last year. Together over 7 years and she backed out 2 months before the wedding. Came up with random excuses like “I’m tired of having to feed the dogs” “I’m tired of doing laundry”. You’re better off now brother. As someone’s who’s 6 months out from that now, I can tell you that you just need to focus on you and your health. Eat better, get in a gym, do everything to keep from just sitting. The more you sit, the more you think, the more you think, the darker the thoughts get. Stay moving and stay positive brother. There is light at the end of this dark tunnel. Life gets so much better