Infected tooth, can I take dicloxacillin?

No. There are better options for tooth infection. Ask your dentist.
Infected tooth. Don't take any prescription medication without being seen by a dentist. Use warm salt water rinse for now (if no high blood pressure) than see a dentist asap.
See dentist. Do not take anything not given by your dentist or doctor. You must also remove the source of the infection to truly treat problem, see a qualified dentist.