Slkcal......this is just a suggestion, but it could make a difference.
If your mid-to-low back is hurting, that means you really have to work to protect it no matter what you are doing. The best way to do that is to try never to bend over with a curved back when you are, say, unloading the dishwasher. How to do this is simple: stick out your bum as far as it can go. I know that sounds crude, but seriously, if you do that your back will not be engaged, and will remain flat, and won't be as likely to hurt. I do this all the time, no matter what I am doing, every time I bend over. It makes a huge difference.
Same thing when you are picking up anything.....anything at all, even a little thing....from the floor. Do it the way weight lifters do: squat down, then tilt your head back as far as you comfortably can and look at the ceiling, and keep your head that way as you come up again. this forces your back to stay straight and makes you use your legs instead of your back. Your legs will really feel it (which is good....they will get stronger).
Most people use their backs wrong and use them for things that really the legs should be doing. If you always keep in mind to protect your back, no matter what you are doing, it will change things.
the other thing is: stretch out your hamstings (the tendons in the back of your legs). The more stretched out and limber you are, the easier it will be to protect your back.
As for not seeing results....don't give up. It takes time. If you give up you defeat yourself. If you keep at it and praise yourself for doing each little bit you will see results in time. The reason you felt worse after working out is you are not used to it. Keep at it and your tolerance and strength will build.
Best of luck.