I've dealt with this for about 50 years. Until about 30 years ago, I would be down for several days to over a week at a time, several times a year. Then my wife was referred to an MD who was a physical medicine and rehabilitation specialist when her back was giving her trouble - I went along and listened to the guy and did what he said and went for years without missing work and even the occasional fairly serious episode now is quickly cleared up.
I'll give you advice that I don't think can do you any harm and if it works for you like it does for me, it will be a big help.
Sometimes some advil is good for reducing inflamation, but ALWAYS have food in your stomach well before you take it. Don't take it long term - my doc says it's hard on you.
Now the stuff that has worked for me:
1) Ice the painful area to reduce inflamation. Freeze water in little paper cups and tear away the cup as the ice melts. Get wife or kids to do it (kids love to administer a little torture to dad). Try to hold out for a whole cup - it usually numbs up enough that you can stand it.
2) Don't sleep in a soft bed and always try to keep the arch in your back. When you sit down always use a lumbar support - a small rolled up pillow works for me - you can tell when it's in the right place.
3) This is the first thing to do whenever you feel low back pain - lay down on your stomach
and slowly do a pushup, keeping your pelvis on the floor. As you push up, try to relax into it - if your pelvis lifts up a little, stop pushing up and let your pelvis relax back down to the floor. This should concentrate the pain. Don't kill yourself but try to do 5 or 10 reps -you'll be able to go a little higher each rep and you'll probably feel relief from the first session. Ice if you
think it needs it and do it again in 30 minutes to an hour. This back bending is the one thing that has consistently fixed me up for lots of years. After healing up from this episode, you'll feel back pain again in the future, but if you'll do the back bends at the first sign, you'll probably head off a nasty time. The explanation I got is that bending forward and lifting things squishes the disks toward the back and this exercise squishes them back where they belong. Lots of people have bulging discs but until they bulge that tiny last little bit and contact the nerves in your spinal column, you never know it - but man, when it hits the nerve
you know it in a serious way.
4) There is a good, simple stretching exercise that that will help as soon as you can tolerate it (when your back is hurting, you tense up the muscles in the area and they get stiff and pull on your spine, making it worse). This stretch is also good to do daily to prevent the problem. The stretch: Lay on your back on the floor, leaving your left foot on the floor, lift your left knee a foot or so off the floor (this drags your foot toward you) then put that foot on the floor on the right side of your right leg. Keeping your left shoulder on the floor, grab your left knee with your right hand and pull it to the right and down toward the floor. As you do more reps and learn to relax into it, you'll get the knee close to the floor. Repeat with the other leg, do 5 or 10 reps and you'll feel it stretching your butt muscles. Those are some big muscles and they can pull on your back if they aren't stretched out.
Try the three things: ice, pelvis on the ground pushups and the butt stretch (also stretches across your back) when you can do it. I bet it will help and if it doesn't, it shouldn't hurt you
at all.
Good luck with it - I agree, that helpless feeling sucks.