To put it quite simply...
You have to play with other musicians, preferably someone who's just a bit better than you. Playing with others will increase your ability 10 times as fast as it will sitting alone in your room and practicing.
Record yourself. Record a rhythm track and try to jam over the same track...record this also. Put it away for a week, and then listen to it. You'll hear areas where you nailed it, and areas where you need improvement, plus this often leads to song writing ideas.
Play some open mic nights in your area, The fear of performing in public will definetly force you to practice.
Subscribe to a good guitar magazine. Getting that issue every month in the mail helps keep the juices flowing.
Read Rock & Roll biographies. Always a great source of inspiration.
Work on areas you may not like..such as the pick and fingers approach (hybrid picking) and finger picking chord and melody changes....pedal steel bends on guitar are useful in any area of music.
Know at least 4-5 different ways to play every chord. Understand that instead of the usual open G chord, you can play a little 3 note G chord at the 7th fret looks like the standard D shape)
For inspiration, I recommend listening to the Hellecasters, Danny Gatton, and the Ventures. The Ventures are literally an encyclopedia of guitar riffs...great learning source...and finally,
Practice till your fingers bleed. Haha