I'm so sorry you're going through a rough time with your husband.
I think many of us feel the same way. Just when something is going right... bam! Something "goes wrong".
I guess what we have to remember is that, while some things are out of our control, other things aren't.
We can work hard at a relationship, but if the other person isn't "there", we're screwed.
But our food choices are completely within our control. As is our choice to exercise.
Go ahead and feed your body some good healthy food. And start your exercise program. It won't solve all your problems, but it WILL make you feel good. It's something you're personally in control of, and that's huge.
Sending you a big hug, and hoping that things with your husband improve.
Hang in there, hon.