How To Treat A Painful Foot Blister?

After exercise 48 hours ago, my foot blister is really painful. throbbing and im unable to sleep. it is infected as i have had the same pain in the past. I have a packet of flucloxacillin 500mg pills. I believe i can take these antibiotics to cure the infection? and how many pills do i take in 24 hours? is it 4?

Really need some advice ASAP please