I have been playing for Many years now. and your acoustic guitar improvement is pretty great.
if you play mostly metal i would suggest to work on downstroke selecting, it gives the sound much more "punch". for solos:
choose a guitar solo you need to discover (for begginers i would suggest fade to black through metallica, generally solos in heavier things tend to be very difficult) take the single, and practice having a metronome.
start slow and progressively start to perform quicker before you get to the level where you can play it with no problem.