Water harbours so many infections- I think you have caught one and the awy it's speading is alarming.
I would advise-
Inj tetanus toxoid
IM stat, you can omit it if you have taken one in past 5years for any reason.
Cream Fusidin/Fusiwal apply BD.
625mg 8Hourly for 5days.
Start before it's too late.