One of the best ways to "break out of a slump", with regards to soloing, is to introduce yourself to a new sounding scale. Although in the pop, rock, country, blues, etc. genres, guitar solos are usually based entirely on blues and pentatonic scales, there are times when different, more exotic sounds, fit in quite nicely. One of these more unusual sounding scales, the harmonic minor, can add an altogether different sound to your solos, and might just provide you with the inspiration you're looking for.
The following lesson should give you the ability to learn to use the harmonic minor scale in various settings.