i dont know what i have , im scared i have no income husband abandoned me and i need an answer and help

i had unprotected sex and had a facial boil appear then become open sore and huge. i also have for years problems with menstrual cycle they put me on prednisone and something to bring my period back after not having one for 6 years . i am so confused all the mrsa facts say it could be many things as cat scratch infected which i also have my cat that did scratch me . i also traveled on a plane last week and came home to this appearing 2 days later so all the mentioned are factors of mrsa and which id the one that caused my infection ?