Antonia. I think many of us here are in the same boat, if we fully acknowledge our feelings.
I don't think it is at all straightforward. We loved these people deeply for a long time; most of us were somewhat co-dependent with a rather needy person, so there is also some need in us we have to acknowledge, as well as love.
We were emotionally intimate with them, and that, as you get older, doesn't come so easily. Hard to start over, especially if one tends to be reserved
We were dumped in a particuarly brutal way, for another model, and there is also trauma to heal from.
Time helps, it really does, although the passage of time seems endless! Therapy helped me a lot, talking it over with someone who is pro-marriage, and pro us. Some therapists are not so sympathetic, but I had a great one, who made me see myself clearly, but who was kind and helped me to a better place. Get one you like - respect isn't enough.
And finally their failure to grow up, their unfailing nastiness [in my h's case] finally starts to seep through as well. You start to look at the person and see their faults.
Yes, more than 5 years later I still love my h; no I am not in a relationship, and I am fine about that, but I don't want him back, and I could imagine having another relationship in a way I couldn't even a year ago.
I don't need anyone else, and would only like someone if we make each other feel good about ourselves, and each other - no more angst and immaturity thank you! I have no overwhelming desire to wash another person's socks!
You will continue to feel better about yourself, with occasional set backs, and you will look back and see how you have grown and become truly self reliant. It is a great place to be, like a mountain top. It is the climb that is painful!