I would require further information to give a clearer picture for the best action to take going forward. I would like to know when the bite was felt and has the rest of the bite marks and blisters come after that incident or was it there prior. I would advise you to go to the ER since it seems to shows a character of spreading over your body for which going to the ER and having it checked would be beneficial.
Next Steps
I would advise you to go to the ER and have the wound checked, also take TT injection if you haven't had the coverage in 6 months also having your blood routine checked.
Health Tips
if the spread increases and if it is associated with pain, darkening of skin, itching sensation and further worsening, Kindly visit the ER at the earliest.