Immediately make an appointment with your doctor. That much pain means something is wrong! The sooner you get started on fixing it the quicker it can be fixed. If your pain is caused by a pinched nerve, bone/spine deformities it will only get worse if you wait. If you have an infection that too is spreading while you wait.
I have endometriosis and suffered chronic low back pain for years. I've also had irritable bowel syndrome which also causes chronic low back pain.
Tylenol is not an anti-inflammatory medication. Try ibuprofen or one of the other OTC anti-inflammatory medications.
Not to scare you but to let you know how serious this could be, my cousin's wife, thought she could wait out her pain and she died. She had a UTI which had spread to her kidneys by the time she went to the ER. She did have a fever and was otherwise in poor health.
If you don't have a fever you probably don't have an infection. You could have kidney stones although that pain is usually sporadic. I think the pain without fever and remaining constant is most likely related to your skeletal system. I would start with my physician who could then refer you to the appropriate specialist.
I have used chiropractic and it does sometimes help but not always. It's good to know specifically what is wrong before deciding to use chiropractic.
I don't understand how you could suffer really bad lower back pain for 6-8 weeks without seeing a physician. If you don't have insurance you can go to a county clinic where they charge on a sliding scale. Please see a doctor soon! You may causing your body more harm as you wait.