Sorry this is happening to you. It's been a couple of days. Are things any better? My son had the motherload staph infection. It started as a small rug burn he got in school that he put a band aid on. He got it on the last day of school and he's pretty independent so he was kind of caring for it himself. He showed it to me an it was like any other small wound. No big deal. He did keep a band aid on it though. Two weeks later he showed it to me and holy heck. That thing was a festering crater. And then there were other sores around it. On the same leg. I took him straight to the doctor who determined it was staph and gave him an antibiotic topical ointment. We used it. But within 24 hours, he had craters and eruptions all over his body. He got the big gun antibiotics at that point as the staph they said was in his blood stream. Antibiotics cleared it up in about 3 days. Completely. Thankfully. So, that is kind of a 'staph' story to give you perspective.
My husband had something called cellulitis. See if this rings any bells. That too starts with staph or strep on the skin. A little break in the skin and the bacteria gets in there and takes off. Cellulitis is a deep infection of the skin caused by bacteria. Things blow up and get swollen and painful. For my husband, it was his ear. And then it started to go to his face and toward his eye and THAT landed him in emergency care to stop the infection. He got well with antibiotics. But they were very strong. https://www.hopkinsmedicine.org/health/conditions-and-diseases/cellulitis That link is helpful. It also states that cellulitis is common in legs (and therefore, feet as well).
Since both of the above are treated with antibiotics, this may be why they went that route. Have they helped?
Your chest hurting is always worrisome and it's important to get that checked out. It 'could' be your anxiety over the pain or a pain response as well. They'd likely have seen some indication of a spider bite on your foot if that was the case.
Do you have a primary care doctor you can check in with at this point?