I'm thinking of leaving my husband of ten years over his mental health issues
Why would you leave your husband for something like this?
I feel like he doesn't give me enough attention because of what he goes though.
It is ok to leave a relationship that you don't feel works any longer. Relationships can be very delicate, and require a lot of work. If your husband's mental health situation is too stressful for you than make the decision that makes the most sense for you.
The problem is mostly in my head when it comes to staying with him.   Im going to organize the divorce papers tonight.
I would advise if you already haven't tryied to work it out with counseling or by talking it out with him.   If it is still unresolvable, than a divorce may be the best thing.