Am I hurting myself by staying with someone who can’t promise me a future?

Hi everyone,
I’m writing this because I feel exhausted and I don’t know if I’m thinking clearly anymore.
I (26f) love this man (28m) with all my heart. I don’t think I’ve ever loved anyone the way I love him. I know he loves me too, and that’s what makes this even more painful.
Because of our circumstances, he told me he can’t fight for a future together. He isn’t saying this because he doesn’t care he’s a very rational person, and he believes some things just can’t work, no matter how much love exists.
He even gave me the choice to walk away. But I couldn’t.
We are still close. We have sexual intimacy, but emotionally something has changed. We still talk, but he doesn’t call me “my love,” “my heart,” or “my soul” anymore. He used to, before we had a serious conversation about our future. After that, those affectionate words almost disappeared.
The last time he told me “I love you” was after I gave him a gift. Before that conversation, he used to say it more naturally.
Every day I cry because my heart hurts so much. I don’t want anyone else. I wanted him to become my husband. I imagined him being the father of my children. But sometimes life doesn’t give us what we want.
I know many people will probably tell me to leave. But right now, I honestly can’t. Even if this relationship only lasts a little longer, part of me feels that spending a little more time with him is better than losing him completely.
Am I just delaying the inevitable? Or is it okay to stay with someone you love, even when you know the future probably won’t happen?
I would really appreciate honest advice