I don't know if you are going to come back, but you mentioned you were having some seriously bad feelings because of this.

Crying for days, sleeping trouble, trouble focusing on work, and a hospitalization from worry over her? I think you need to take a step back and take these results over your worry more seriously than you are. You wrote a huge paragraph about your feelings and relationship with sakura, and your worry over her. How hard things have been for her in fire emblem, and your anxiety if she is going to stay because of your dream. And in the end, you share one sentence about how this has effected your life and mental health. In one sentence you say you are having this crying and work/sleep troubles and a hospitalization.

Well, that one sentence was the most important part of everything you said to me, and it should be to you as well. You are suffering over this. Sakura, and everyone else, does NOT want you to suffer. You need to get help with your anxiety over this.

I am going to treat Sakura as a real individual for just a minute to say one last thing. If someone said they had a dream about their partner leaving them and now they were worried, I would tell them don't. Just don't. It was a dream manifested from pre existing anxieties about your relationship, and it does neither party and good to dwell on it.

Actually, worry is just toxic in general. I hope you can find some comfort and peace soon, without worry.