How to move on from a loved one

For those who had partners unexpectedly passed away, and then moved on with your lives and found new a new person, how did you do it?? It’s been about a year since my fiancé passed and I still cannot see any roots in my future with anything and I’m 27. I know everyone heals and grieves differently but I feel like I owe it to him to not move on and that he was the only one for me or that whoever I may meet will never be as special as him or will never meet to his expectations that I will probably always look for. I feel like I have baggage that no one will want or that it’s a icky topic that is best avoided to not ruin conversation. If roles were in reverse I would have wanted him to move on and be happy, but again I feel shameful and guilty to even think or do so as if I’m betraying him and our love. ❤️‍🩹 He was my first love and was my world, and life just has been very grey without him.