Too much exposure to X-rays can be damaging to health, but the amounts that are used in X-rays are quite small. The reason the doctors hide behind a screen, or in another room when they do X-rays is because then they would be exposed to them hundreds of times a year, for year after year after year. If it wasn’t for the screen, then that could be harmful, but I doubt that the exposure that you are getting will pose any significant risk to your health.
I’m very sorry to hear that you’ve had so many x-rays. Are you having problems with your back?
X-rays are damaging, yes, but at the doses used medically you shouldn’t worry about it: the increased risk of cancer from it is EXTREMELY low. The doctors and nurses who take x-rays leave the room each time because they would be exposed to x-rays every day, so that could be more of a problem.
Having x-rays can slightly increase cancer risk, which is one of the reasons that the person doing the x-ray leaves the room, but they are doing x-rays all day several days a week. People should have as few x-rays as possible over their lifetime, but 9 isn’t really that many and I’m sure your doctor will have considered the risks and benefits and so you probably shouldn’t worry about it.
Any X-ray involves exposing yourself to a small amount of ionising radiation – which can damage the cells in the body. However, the amount of radiation in an X-ray is very small, and it is also weighed against the advantage of learning about what is wrong with you! Also, your doctors would never knowingly overexpose your spine to X-rays, so they will be able to explain to you why each X-ray was completely necessary.
I think you shouldn’t worry about the x-rays you have been exposed to, because the amount that is used in a spinal x-ray is quite small and not dangerous. I hope that your back is not giving you too many problems though, considering that you have most likely had 9 for some reason!