From your history & clinical description, the 'lump' seems to be either an abscess or a cystic lesion that is secondarily infected. Go ahead with the amoxycillin
..it may resolve the problem; you may want to add on some anti-inflammatory like ibuprofen
the dose depending on your body weight & your local pharmacist should be able to help you.
The rash between the thighs appears fungal. Do give a 2% ketoconazole
cream (eg nizoral
) a try application locally twice/day for a week.
If no respite in 48 hrs, do see your local GP. That abscess may require to be incised & drained which should be a small procedure easily taken care of in a GP clinic outpatient.
Cheers & wish you good luck, speedy recovery & greaat biking days ahead!!
Dr Praveen Rodrigues MD
, Cosmetologist, Venereologist
Vikram Hospital,Bangalore, India