#1
So ive been playing for about 3 years, but the last year i havent really had a guitar teacher [not by choice]. I can play things pretty well when i put my mind to it and know my scales and my strength would actually be improvising oddly enough.

Anyway as of the last 3-4 month ive hit a wall. I feel like i havent been progressing any at all and i play plenty enough to where i ought to be. What im looking for is some advice on different things i should be doing to help get better chops and advance my playing, whether it be songs i should be learning or whatnot. To let everyone know about what im capable of, my daily routine goes: [without Solos]

In My Darkest Hour-Megadeth
The Unforgiven-Metallica
Seek and Destroy-Metallica
Enter Sandman-Metallica
Mechanix-Megadeth
Holy Wars-Megadeth [only up to the first Marty scale part]
Master of Puppets-Metallica
The trooper-Iron Maiden
Hollowed Be Thy Name-Iron Maiden
Battery-Metallica
Breadfan-Metallica
Everlong- Foo Fighters
Killing In the Name- RAtM
Flake-Jack Johnson
Save Tonight- Eagle Eye Cherry
Upside Down- Jack Johnson


Basically i run through at least 10 of those a day, alternating between on my acoustic and electric and then do a little improvising, usually to the master of puppets interlude, Tears in a vial by megadeth, or Turn the page by bob segar.
#2
Seems like you have technical skill down.

Sit down and find a theory book/online theory courses, and learn your scales. It will tremendously help your improvisation skills and therefore you will run into more potential riffs and melodies.
#3
The solos in these songs are not the most difficult. Learn one solo at time, master it, then jump to another solo. I would start with Enter Sandman because it's the easiest among those in my opinion. Practice slowly, and make sure the notes are clean. Another thing you should do is learn technique, theory, and how to incorporate both of them in your playing.