I played guitar for 6 years, but now I am stuck.?

I never took lessons. I only taught myself. In doing so, i went right to learning songs, not practicing technique. I am decent at playing, but by no means excellent. I would consider myself intermediate. I can play solos but not flawlessly or with complete ease. I struggle with pinky use and speed. I seem to not be progressing lately in my playing ability. Any suggestions how to take my skills to the next level and continue to better myself?