A different kind of grief

I’m experiencing a different kind of grief following a breakup and would much appreciate some thoughts on the matter and advice as to how I can move on.

For context, I (21F) dated a colleague from work (21M) for about three/ four moths. In the beginning we met more sporadically, but towards the end (the last month) we were the first person we texted each morning and we told each other good night every evening. We were invested in each others days and had some sort of contact throughout the whole day, asked questions, sent videos and pictures from out life and funny videos we found online.
We really got to know each other, had similar interest, background and childhood, wanted similar things out of life. We were on the same “wavelength” and understood each other, we laughed a lot. We had a shared view of the world and I really felt that he got me.
Our way of being close became natural; the way we held each other, the way we were naturally close when we were in proximity to one and other, the way he kissed my forehead before we fell asleep, and the way we hugged goodbye. He became a safe place for me, someone who made me calm. Everything was easy with him.
We never officially dated/ were a couple but it was that conversation that ended things between us.
We knew each other, not completely, but enough. Enough for me to have started developing feelings for him, I could picture how a life with him would be, and i wanted to choose it, I wanted to be with him. We talked and he said that he had had a “nice time” getting to know me but that he hadn’t developed any feelings on his end.

I don’t feel that any of us did anything wrong or should have done anything differently. But in a way, I’m grieving. With the last person i dated, we ended things before we really got to know each other because of distance. That was really hard to get through because it felt like we never got a real chance to see if it could work, and the though of the possibility of “us” not being closed/ over was hard to live with.
With him it’s different, we took our time and got to know each other but the feelings wasn’t what they needed to be, at least on his end.
He had many great qualities that I’m looking for in a partner, it’s not that I’m certain that no one ever will come across my life that might share some of them, but that’s not my worry/ why I’m sad. A person can never be replaced, and i wouldn’t want it to be that way either.
He is written on pages in a chapter of the book of my life that has meant a little extra to me. I had hoped that he would continue to be a part of my story, but he won’t, at least not in the same way. I don’t want a person with his qualities, I want him.

The thing I find hard is that I’m grieving a person that’s still alive. We will be working in the same building, having the same friend group, and seeing each other again. I will have some calibrating to do regarding the way he is a part if my life, but i still want him in it. (We broke things of less that a week ago and have been no-contact since then, per my request. But we will se each other on a trip with shared friend in two weeks).
I would hate for us to become strangers. Our history will never be a burden, it will be something that I, in a way, will be proud of to look at. We dared to let the other person close, to be vulnerable and he was honest enough to tell me about his feeling.

But I’m grieving him, that we weren’t right for each other, because I desperately wanted him to be, i wanted to choose him.

I hope that some if you might resonate with my story, maybe you have lived something similar. If you would like to share, i would love to hear about it. To know what made it easier for you to move on. What should you do with this kind of grief?

It’s not my first rodeo being heartbroken, but it’s my second, and that’s still a very low number if rodeos :)

Kind regards!