Is it safe to work with condochondritis?

[LolaLeigh]

About 5 years ago I was working and suddenly had this horrible pain in my chest. I thought I was having a heart attack but it turned out that I had strained the cartilage in my chest due to lifting more than I should have. I recovered from it and haven't had issues up until now. I recently got a new job as a CNA at a long term senior care facility so I'm lifting a bit more than I'm used to. The pain in my chest is slowly getting worse again like it did before but I love my job and don't want to have to quit. Are there any exercises specifically for this part of my chest? I just don't want to have to go to the ER again because I can't afford it. Any suggestions or experiences are greatly appreciated!