In addition, treatment for PID always must include a drug against chlamydia, even if chlamydia testing is negative. Neither the shots nor the metronidazole is active against chlamydia, so this also suggests you're not getting all the treatment you need. This is another thing to discuss with your doctors. Don't be shy about asking these questions!
This sounds like they are treating you for pelvic inflammatory disease (fallopian tube infection), which is usually due to either gonorrhea or chlamydia, apparently gonorrhea in your case. Other bacteria often are involved at the same time. The shots may have been cefoxitin, which covers both gonorrhea and many of the other possible bacteria; metronidazole also covers additional bacteria. (If the shots were ceftriaxone rather than cefoxitin, that's good for gonorrhea but not the not the other bacteria that could be involved.)
It can take several days for PID symptoms to improve, but if your abdominal pain isn't getting better yet, it's possible you need still more intensive treatment, such as IV antibiotics in the hospital.
However, the vaginal area swelling and "crusts" definitely are something else. I'm worried that in addition to gonorrhea and PID, you also have new genital herpes. This won't respond at all to the antibiotics you are taking.
I recommend you return to the emergency room or an urgent care clinic right away, preferably today (even though it's Sunday). If you have herpes, it should be obvious on examination; they can take tests for it and start you on anti-herpes treatment if that's what it is. They can also judge whether your PID is getting better or if you need more intensive treatment.
I'm also a bit worried that the ER doctors may not be entirely up to speed on PID, gonorrhea, or herpes. You should insist that they call in an infectious diseases specialist and/or a gynecologist to further advice on diagnosis and treatment. (Consider printing out this reply and showing it to your doctor[s].)
In the meantime, anybody you have had sex with in the past few weeks needs to be examined and treated for gonorrhea, and maybe evaluated for herpes as well.
Please return with a follow-up comment and let me know how it goes. Good luck!