I would like to ask someone about my back pain tell them all my symptoms and what i have been doin and hopeful?

i am an overweight 28 year old female i have almost always in my adault hood had back pain ffrom being overweight i assume every once in a while i will do something that irriates my back more than normal and b in exta pain for a couple of days but it has always gone away within a couple of days i recently had started excersizin by doi the llatest zumba and as i was jumpin around i had stepped just rght on my foot and just felt this terrible pain go up my back and down the back of my legs it was a real sharp pain now i work at a place that i am on my feet for 8 hours a day and i am constanly pushing and pulling meat products off a line and tossing them i worked for a whole week about in tears everyday everynight sleepless night with agonizing pain it was a pain of like throbbin and i guess muscle spasms that would just not go away and everytime i stepped dwn just rght on my left leg it would shoot a pain dwn theback of my leg i had went to see my doctor she had said it was probably just a pulled muscle and had me take a lil time off work and do stretchin it just didnt seeem to help a week went by and it was time for me to go back to work but i still in alot of pain so i had went back to my doctor and explained to her by this time i i was having numbness in my left leg and like a tingling feelin in my foot on the left side still sleepless nights it bothered me to walk stand sit for more than a half hour at a time my doctor had wrote me out a slip to start physical therapy so now i am currently in physical therapy 3 days a week i am goin this back pain is very uncomfortable i try to stay as active as i can with being able to sit and stand as i need to this has been goin on now for about 5 weeks and does not seem to be gettin any better and actually i have recently started having pain in my hip on the left side also this pain feel like my hip needs to be popped but it just will not the physical therapist tried to pop my hip but it just made my lower back hurt even more and made my leg on the left side . i have not yet been sent for a mri or anything like that now my question is after all i just explained what could be wrong?? i have had several people tell me it could be a bolging disc and a pinched sciactica nerve please help me