This situation must be making life very unpleasant and you shouldn't have to suffer when there are treatments available. Your symptoms sound to me like you are experiencing some form of an anxiety disorder.
Treatment often consists of medication and talk therapy.
Sounds like your fear of death was not always there. That is, you may have at first only feared cancer, but the anxiety might have spread to include fears of being murdered, and so on. I would suggest that you not wait much longer before getting some help. Getting treatment sooner than later usually equals a faster recovery.