The views expressed by me are for educational purposes only and do not establish a doctor patient relationship.
Thanks for your question.
The antibiotic z-pac can cause diarrhea and soreness as side effects.
the lymph node or the bump is likely due to the viral infection. this usually gets better over time as you are noticing shrinking in size.
exercises can precipitate the groin muscle strain which can explain the hip symptom
Overall, this is not concerning and patience is required for full healing process ( should 2-3 weeks).
You may consider reducing the exertion on your hip, groin lower stomach by moderating exercise schedule till the soreness subsides.
drink plenty of electrolyte rich fluids.
that is what happened.
that is unlikely.
as node get inflamed mainly from infection.