When it comes to your "teacher" problem, and sound advice all around, I greatly agree with going to your instructor (it may be hard becuase he is a freind) and let him know what you would like to acomplish.

I "teach" also and the first lesson I have with any of my students is the "Interveiw". This first lesson is more about talking with a potential student and asking them what they 1) already know music, guitar or another instrument 2) do they even want to learn music notation, theory, etc. 3) what style do they want to focus on first (ask themto bring me 3 songs they enjoy and an explanation of why they enjoy it--helps to develop a lesson plan gfor chords, scales, soloing etc. (a good 6 months of lessons depending on the student)
4) gound rules for the student teacher relationship i.e. student must practice (not just 20 minutes before the next lesson) to continue learning and Teacher must relate and instruct the things which we have agreed upon.

I try to keep it a give and take and also realize that eventually the student may come and ask to learn theory and notation but the only thing any new student can think of is "I just wanna be able to play!" We have all been there done that:)

Pol and EB -- quitting is an option. One I don't beleive in but if you are not getting enjoyment now -- take a "vacation" first. Litterally put your guitar away for a week or 2. Don't touch it. Try not to listen to the "guitar inspiring" songs you usually listen to. Give yourself a break. Yes guitar playing is fun, great, awesome and inspiratioal. But it does take work, and as in life all work and no play can make music dull and boring.

Just my 2 cents.

I hate to see others struggle and dealing with the "Quitting Demon". I wish ya'll the best of luck in recapturing your muse.