How many X-rays is it safe to get in what period of time.
None, in any period of time.
The amount of X-rays you were subject to is just plain madness. But it tallies with the 'doctor' smoking in the surgery.
Having said this, I wouldn't worry about what's happened so far, statistically you're ahead of the game, but there is mounting evidence that doctors should make minimal use of X-rays. Where it's the lesser of two evils, there's a case for using them, but for routine examinations, the use as you describe shows a clear lack of awareness of the latest findings.