The same thing happened to me, and I've been playing for 2 years as well. No I don't really know this thing very well, but I can tell you what I understood. IF you take the c major scale and you play it over the C major chord, you will find out that it doesn't sound false.(i THINK)
i can tell you, from experience, that you can use the BLUES SCALE, because it is easier to improvise solos. A lot of solos are made with notes from the blues scale. You can try to improvise a solo over a song. it's easier in blues.
If the song is in E, you can mix together the notes in E Blues SCale. With a little practice you can make cool solos.
By playing scales you can also improve your speed, technique, and you can do warm-ups.