<human>: First off, my last day at my job (grocery store) was Nov. 7. There I was lifting 50-lb bags of cat food and those 24-packs of water off the bottoms of carts and putting them back in. A lot of back strain, and I have back problems. 9/10 pain at its worse. So I quit.

I recently started a new job (retail). I've had 4 shifts (about 2 weeks). Compared to grocery store, it's worse. I'm 8/10 pain, and 7/10 at its best. Whereas it took ~7 mo to reach 9/10 at grocery store, it's taken 2 weeks at retail because of all the twisting and bending and turning. I'm in so much pain I just cry when I get home.

I don't know what to do. I've only been there two weeks, and I'm already contemplating quitting. I'm also contemplating going back to my first job (fast food - the one with carhops) which was so awful - schedule changed every day, so many people, have to be in the cold for a long time, manager never there, this thing that happened with my foot. But there's a new manager there and two of my friends work there. And it didn't give me back pain - or at least, not as much. Not much bending, barely any twisting.

Give me advice. Should I quit or stick it out and see if my body gets used to the job/pain recedes?

(Don't know if this is important,  but it is a factor: switching from fast food to grocery store didn't cause pain, even with the excess bending and lifting and twisting. So this is different.)

Could you distill the essence of the text into 1-3 sentences?
<bot>: Quit my painful job and entered a more painful job. Thinking about quitting and going back to first job (no pain, but shitty in every other way).