And it worked out great.
You just need to get away for a while to vent the frustration.
It kind of weird though; while I was away from StarCraft I got this annoying feeling that I was just being too hard on myself. I've always been pretty competitive and a perfectionist in everything I do (might be because of my work and education, I'm an MD) and in StarCraft it isn't different; I try to outperform myself everytime in every single thing I do, and that also extends to my gameplay. And it paid off... By wearing me out (LOL). I think that a lot of what happened was because I was so stressed by work; as I said I'm an MD who works in a small hospital in the countryside in Chile. I'm the hospital's subdirector and I have at least 3 ER shifts per week (24 hrs), so I think all that work just accumulated too much stress in me and eventually that had to blow out. So it did, and I'm glad it happened because it helped me identify what was going wrong.
So after I kind of got an idea of what was going on, I paid a visit to a good friend of mine, who is a psychologyst, suggested that I played for medium periods of time (no more than 7-10 games in a row) with a towel on my lap. Whenever I got frustrated I was supposed to take the towel and just vent my frustration on it. After squishing it hard from one side to the other I feel so worn out and relieved that all the frustration is gone and I can keep on playing. Even my gameplay improved: I got promoted to masters! :D
Besides playing, I also went back to my other things. I begun making my VODs again; this time I'm playing Skyrim and Diablo 3... (yeah, Blizzard FINALLY sent me a key), besides begining to prepare my SC2 netcast again AND going back to modding Artosis'es stream chat. And it is so rewarding to go back to all what's good and cool in my life: Gaming.