First, a disclaimer: you should probably see a doctor. It's most likely a muscle strain/tear, but it's also possible you did serious damage, such as injuring a disc, and you should check it out before you make it worse.
Originally posted by: Connoisseur
So i hurt my lower back when doing squats about 2 or 3 weeks ago.
It's obvious, but worth repeating: spend some time learning proper squat form. It's certainly possible to injure yourself even when doing things properly, but far less likely.
Starting Strength has some 60 pages of text, photographs and diagrams dedicated to explaining the squat and is one of the best resources I know for learning the motion.
Originally posted by: Connoisseur
Tonight I decided to try squats again with lower weights but it still hurts.
It's good that you went with lower weights, but if your back is still stiff and hurting, it's not ready for proper squatting. Rest is really the best remedy.
If you do any exercise at all, do something that requires almost no weight (such as back extensions) and do it for a LOT of reps. The only goal is to flush blood through the muscles in the back to accelerate healing.
Originally posted by: Connoisseur
I've read that usually it only takes 1-2 weeks for the back to heal but the pain is still there (worse now because of the squats).
Actually, the back is notorious for being very
slow to heal. 1-2 weeks is the absolute minimum I'd give it, with closer to a month being more likely to get back to 100%.
Originally posted by: Connoisseur
Short of seeing a doc (which I may do anyway) any suggestions on what's wrong and how to fix it?
Rest, advil and rehab exercises. I've been dealing with lower back issues myself as I describe in my
lower back pain thread. My issue is tied largely to serious lack of flexibility, mobility and glute/hip/hamstring activation (a result of a sedentary job), but even if yours isn't, the thread contains a number of links to good exercises & stretches. These include dynamic stretches to use before a workout, static/PNF stretches to use after a workout as well as some squat technique videos.