I've been playing guitar for about 3 years now, and I've been told that I'm just about an intermediate player. (Which I believe so myself)

But for about half this year I've felt like the progression that I've been making as a guitarist and and a musician has significantly slowed down. I practice and practice every single day to either the point of boring myself with the repetition of effort. For these 3 years I've basically been self-teaching but unfortunately I feel as if I'm having improper practice.

There are serveral areas in which I would like to improve, such as:

- Arpeggios / Legattos
- Improvising
- Sweeping
- Scales
- etc..

So far I only know one scale (not sure of the name), a few technical songs (such as: The Sound of Truth, a little bit of The Hounds of Anubis, and Relentless Chaos) but I wish to be able to create riffs, licks,etc. along with having better creativity.

The solution that I thought might help is to have a solid understanding of guitar Theory / Music Theory for the guitar, but I am not exactly sure if this is will help me at all.

So my question would be:

Could someone who is experienced with the guitar or someone with enough knowledge point me in the correct direction so that I can advance myself as bothe a guitarist and a musician.

Keep in mind, I'm not trying to play a generic style, I basically want to build enough creativity and have a good enough understanding that I will be able to transcribe anything that I have playing through my head to my hands; And, would also like to be able to play ALL different styles of music including Classic.
it seems like a better understanding of music thoer will hep ou understand what you need to practice more and help ou with beign able to play what you think off
i suggest you go to musictheory.net and read through the lessons and use the ear training exersises on there
^^ agreed. I was stuck in that zone for about 2 years. It really sucks, but you have to keep practicing. I recently took music theory classes at my local college and it does indeed help, but you have to use your own knowledge as well. You can't just expect it to instantly make you great at guitar. I remember reading an article where joe satriani was interviewed & he said, "I learned music theory & passed the class, but it wasn't until years later when I finally understood it" The main thing for improvement? I'd recommend to do is find a decently difficult riff to play & try to learn it. As far as arpeggios, I started off with 3 strings & was really bad at it for a while. Find an arpeggio in a song you like. I personally chose the solo from Dethklok's, "Duncan Hills Coffee Jingle" & practice it like CRAZY. After about 2-3 months of practice, I found I was decent at them. Make sure you practice different finger positions as well. As far as improv goes, it's all about scales to me. Learn the minor Pentatonics & blues scales (blues scales are used in metal/screamo) at the minimum. I don't know too much about scales, but most metal/screamo songs use the same set of scales. I would just google search it to find out which.
Get a guitar tutor (if possible). My tutor teaches me all the fun technical things but also describes the theory behind them in a way that doesnt make it tedious or boring. I must admit, some of the therotical side of music is really taxing on my brain, but the way he relates things to songs / scales etc really helps me "get it".
Plus a tutor keeps things fresh by pushing your boundaries with each lesson. When i was teaching myself I had a habit of sticking with stuff i knew and felt was easy to play (for fear of failure i guess), but when you push yourself to learn things that are difficult at first, THAT is when you progress and move to the next level.