Help! My wrist hurts!

[bardofun]

I started playing the bass a year and a few months ago, December of 2005. In the spring of 2006 I took maybe 10 half-hour lessons at a local guitar shop from a college senior majoring in electric bass performance, so I learned basic excercises and techniques. I took a break playing from September of '06 to January '07. A week ago while searching for online bass lessons I saw videos of some guy Dave Crigger teaching techniques for stretching to play major 3rd intervals on the same string(1st fret to 5th fret). So I was playing wrist at a 90 degree angle. The next day when I woke up my wrist was really sore, and when I tried to play my wrist stung and my fingers tingled. Ive been warned about carpal tunnel, tendonitis, and nerve damage from the guy I took lessons from, so I stopped playing for a few days, but the pain still wont go away. It has lessened alot but there is still tingling when I try to play, and pain in the tendon in my wrist. Ive always played alot, sometimes 8 hours a day, but never had pain like this. Is it unlikely to go away? Is it possible to ruin your wrist with one day of poor technique? The pain is localized in the left tendon of my wrist when looking at my palm, but extends to my forearm and thumb. Im just out of college with no good job yet, so I dont have insurance, otherwise I'd be asking a doc instead of all of you. Any help anyone can offer?