do you mind answering a few more questions about it?
how long ago did it happen?
what was it you did that made you suddenly realise it?
do you get any pins and needles or numbness going down to your legs at all?
since you first noticed it, has it got any better, worse or is it still the same as it was initially?
you say bending forward hurts, correct? whats it like bending BACKWARDS?
have you been to see a doctor or anybody about your back? if so, have you had any tests/scans/xrays done?
how old are you?
90% of low back pain goes undiagnosed as there are hundreds of structures that could be the cause, so its virtually impossible to pinpoint the precise problem area. its pretty hard, as I cant see you, to see if the problem could be to do with how you sit or anything, but answering these questions could provide a bit more info. that may be useful.
like some people have mentioned, rest is important, but so is exercise. back in the good old days, doc’s used to just tell people to rest-up and all will be better. that didnt work very well, and most people, although maybe their pain decreased a bit, they couldnt bend 10 degrees to save their lives. anyway, im rambling…