What causes sudden twisting of the body on one side causing pain?

Hello doctor,

I have just started an internship and I cannot take any days off as it is not long so I hope this is nothing serious. I have been lifting some things there, trying to not lift anything too heavy for me, but suddenly I twisted to the side at one point and the left side of my ribs and back started aching. It has not stopped aching, this was two days ago. It hurts all the time but is worse when I twist to any side, bend over, or lean on my left side. I cannot tell exactly where the pain comes from as it moves back and forth a lot from my back to the side of my ribs. I also had rib pain on the same side a couple of months ago. I had not injured myself then I just woke up with it one morning and it lasted two weeks then the pain just started feeling like pressure on my ribs that was constant, light pressure until it disappeared entirely. A couple of weeks after that I woke up with horrible pain in my left side neck that I also felt in my left shoulder. After a few days with that my neck was so stiff and my shoulder was pulled up constantly and I could not relax it no matter what I did and this lasted about three weeks. I went to a physiotherapist on the third week when I finally got an appointment but by then it had started getting so much better that he could not say much. He gave me some exercises and said it was probably torticollis, which is possible I guess but my neck and shoulder were not stiff until after a few days of pain. I do struggle with tension headaches but I do not know how relevant that is. I am mostly worried about this pain I am having right now and I think I can avoid any heavy lifting on my internship as it's in a store and I can probably get help with the heavier goods. I just hope if it is an injury that it does not mean I just have to rest and not do anything for like a week. I was just standing up on a break and I made a sudden twist to the side that's all.