I agree with Rick. Four bust on the same ride is most probably a training/IP problem.
Back in the day, when I was teaching at Riddle, I was one of the IP's that got the "problem kids" (not my name). Ironically, many for their instrument rating and they all got through. So, you are not alone. Sometimes their problem was their IP, some their attitude, and some was that they just needed to be taught a different way. Given the time and the right environment, I could teach anyone that is able to get a PVT their instrument rating. I assure you it is not something that you can not do.
"Checkrideitus" is another big hurtle that is usually overlooked and rarely taught. Yes, students need to be taught to take check rides.
Good luck with your decision.