Anyway, about two months ago my entire right shoulder and right side of my upper back was throbbing and burning and aching all at once, all day every day. It turns out I had an RSI in my rotator cuff (shoulder muscles) from over-reaching for the computer mouse, as I didn't have a proper desk. Combined with that, slouching has shortened my pectoral muscles in my chest and severely weakened my rhomboid muscles in my upper back (the anatomy lesson is free) and reaching for the mouse all day had strained my rhomboids as well, causing all kinds of horrible pain. I basically broke my body.
So, I bought a (very cheap) proper desk and switched to using my left hand for mouse work for about a month, and almost completely rested my right arm, as well as forcing myself into a good posture. Yes, I'm that addicted to using a computer I just switched arms. Oh well.
I have been doing chest stretching exercises and upper back exercises for about a week and the pain is almost gone, I can use the mouse with my right hand again and type at more than 10 words per minute, so I suppose I can start blogging again, if you'll have me.
A warning for others: don't neglect your body or it will punish you without mercy. If you slouch, you might consider doing some of these every day:
Or just, you know, sit up straight like your mother told you.