hi there, low back pain
is one of the most common complain in people who work for long hours especially the onlifting heavy stuff. This could be due to excessive use of back and load being heavy,or due to bad posture while you are doing your job or due to weakness due to any bone pathology. I would advise you to get an MRI
done for your back and also your serum calcium and vit D levels.If you are perimenopausal then osteoporosis
is to be kept in mind. If everything is fine then you could visit a physiotherapist and do some back muscle strengthening exercises.He will also be able to guide you as to the proper posture to be adopted while lifting heavy stuff. You could take few painkillers to assauge the pain for the time being ,taking care to take them only after a meal and never on empty stomach or with alchoholic drinks. Take care.