i have been playing for about 5 years now and i have always felt stuck with my playing , its not just my fingers that are stuck in the same box my brain also seems stuck because when i try to improvise and try to "hear" what i want a lick to sound like its always the same stuff repeating over and over

learning new songs doesnt seem to be helping me that much either i feel like instead of reaching a new level my playing seems to "mutate" rather than improving , is it a lack of theory ?

(i tried my best to explain my situation hope it doesnt sound weird xD)
It might be a lack of theory but I would suggest you should also listen to more new music. Really go out of your way to find something completely different to what you normally listen to: if you're a metal guy, go find some jazz; if you're a blues guy go listen to some chamber music; if you're a rocker go listen to some bluegrass.

Hell, go listen to anything and everything anyway, no matter what you say your favourite is. There is no such thing as listening to too much music.

Another thing you might want to consider if you don't do it already is really listening to some other instruments: things like piano, saxophone, flute or whatever else really have a completely different approach to playing than guitar so take a really good listen to what they do as well.

Finally... I'm not sure what you mean by "mutate rather than improving", could you explain that a little more?
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