This is a common thing I hear from a lot of guitar students. The reason is simple. 99% of the students just want to learn to ‘operate’ guitar. They need the help of others to show them what to play and how to play. Those students just become good guitar operators. They are the ones who always plays ‘Nothing Else Matters’ or intro of ‘Stairway to Heaven’ etc.
Learn the fundamentals, Learn basic Music Theory and harmonic structure of Blues and Rock progression. It will help you to understand the progressions on which most of the songs are built. In order to improve, you must practice regularly. Practice everything at a slow tempo and then gradually work up to speed. It is much better to play slow and clean than fast and sloppy.
Be fluent in Major and Minor scales, modes and 5 pentatonic scale patterns. Get control of the working knowledge of the fretboard. Always learn to play a melody on more than one place on the guitar neck.
Learn to recognize intervals from tone to tone. Concentrate on ear training and aural studies.
Another thing I would like to say is, by knowing the scales means, you should be able to play (all 12 keys) 2-3 octaves of each scale, same pitch, in different places on the neck. You should know which scale works with which Chord progression.
Everyone says they know pentatonic scale, the basic shape. What about the other 4 shapes. How can we connect all those? One should also learn how it is working with a different chord progression and what all notes are there in the given scale etc. Spend time to learn all that.
Learn to improvise with all these knowledge of theory and techniques.
Actual work starts after all these studies. I e writing songs and creating music. That requires a lot of imagination and trial and error work.
PS: No offenses! Nothing Else Matters and Stairway to heaven are great songs. No doubt. But that is not our creation. It belongs to someone else. No matter how well we play, note by note, it has already been done by someone. We are just copying it.
It is good to learn those songs to learn how it worked. But there comes a stage where we have to create something of our own, to survive, to get recognized and respected as a musician.