I'm guessing your car is automatic... the "turn the key and it keeps cranking" is normal to these cars..(yeah I was surprised too). Your initial symptoms are right in line with a CPS problem - lasting two months with a faulty one is unusual though. At 45 bucks for the Bosch brand and 20 minutes install time I'd definitely change it out to at least eliminate it as a cause. "normally" the anti theft gives you two cranks then nothing till you pull the battery cable.. then two more start attempts. My experience with the fob chip misplaced.. the car tries to sputter to life during those starts.