I looked at your two videos. You are off to a good start. I noticed extra movement in your right hand. I noticed that your left hand is somewhat pronated. And I noticed that you hold the guitar relatively low. You will be able to develop greater reach and left-hand agility if you change your sitting position. You will gain greater stability in your right hand if you review correct right-hand technique. And you will be able to play with less effort if you supernate your left hand a little more. Since you are off to a good start, I think you would benefit from getting a copy of Stanley Yates' Classical Guitar Technique from Foundations to Virtuosity. For the foreseeable future, you only need Volume 1, the Foundations. I realize this is a major expense (if I remember correctly, you live in Egypt--I live next door, so I know about the cost of getting books to the Middle East), but I think you are ready for a deep immersion in sitting correctly, and right and left hand technique. You seem to have mastered the basics of reading music and your efforts sound like they are mainly limited by lack of well-trained muscles. So this is the right time to work on technique in parallel to playing pieces. Stanley Yates' book explains the why of everything and goes into great detail about the exact movements and what to be aware of. This is very important whenever you are playing without the supervision of a teacher (even if you have a teacher). I hope this helps.
PS. About Carulli's Siciliana: I have no opinion on the subject. In general, it is more important to develop good tone and proper technique, which is easier to establish first with the very easiest pieces. On the other hand, it is important to enjoy playing the guitar.
I hope this helps.
Yisrael van Handel
Modi'in Ilit, Israel