best thing you can do is save $3000 up for future flight lessons, once you have that amount saved up take time off for a few months from your current schedule and fly at least 3 times a week. Or better get a job at your local airport as a ramp/counter person or in the maintenance shop.
Taking time off from flying for 5 months is not a good approach to learning because you will be rusty and will need to be retaught past flight maneuvers, emergency procedures etc, in the long run you will spend more money by not flying continuously and you will be more frustrated about how little you are accomplish towards your pilots license.
Do I think your instructor is taking financial advantage of you? NO he is doing what is require of a good instructor according to the FAA requirements = making sure you are proficient and safe in an aircraft.
Until you have your money saved up take the time to study all of your flight books and buy the Jeppesen Private Pilot videos plus they have an excellent private pilot book both well worth the money.
Good luck!