I feel so incredibly lonely.

Move on.

From personal experience, all that matters now is the love you show for yourself, self love is the most important. That's a deep wound you described, I too am no longer with the person I love and unfortunately that's by my doing. Move on from it and take care of yourself, you never know what the future will have in store for you!

I’ve found that hanging on just creates frustration and resentment. On both sides. Or worse….the one who no longer loves is just there for the convenience of having a live in maid. I’m sorry you’re experiencing this. It’s one of the most debilitating feelings I know.