I too was/am paranoid about how often I'm getting x-rays and CT scans—especially since I'm relatively young and will need many more scans throughout my lifetime. The last time I questioned my respiratory nurse who works closely with my doctor, she told me that a CT scan is 20x the radiation of a chest x-ray, however the article I link to below from Harvard says a CT chest scan is more like 70x the amount of a chest x-ray.
https://www.health.harvard.edu/cancer/radiation-risk-from-medical-imaging
This article from MSK (Memorial Sloan Kettering) is also very helpful and puts it in perspective.
https://www.mskcc.org/news/scan-safety-radiation-reality-check#:~:text=If%20the%20scans%20are%20justified,time%20interval%20required%20between%20scans.