you are being paranoid, hiv
does not spread by touch, if we assume hiv blood was there on anything you touched it can survive only 10 -15 min outside the human body and by the time you went back home that time has easily passed,you should stop worrying about the hiv and take care of the boil.
but i am thinking you may not stop worrying even after this. so the best way is to get yourself tested for hiv , just go doctor and explain what happened. he will tell you you are overreacting , but ask for hiv elisa
testing. it will 100 percent clear your doubt.