To dream of a cure for a disease represents feelings about a perfect solution to a serious or troubling problem.
Negatively, may reflect a very difficult change or regimen you need to undergo in order to completely fix a problem. It may also reflect feelings about how impossible or beyond your resources obtaining a perfect solution to a problem is.
To dream of longing for to a disease represents feelings of hope for a perfect solution to serious problem you have. You may not believe in yourself enough or need to open up more to others about your problems.