First you have to be willing to separate the person from the disease. If you can achieve that, you will enable yourself to love the person and then manage the disease. It is okay to ask for help, medical, emotional and physical, it is truly something you do not have to take on your own. If the paranoid person becomes violent due to the paranoia you must not feel guilty to put your safety and well-being first.
There are many treatment options for paranoia, the best place to start is with a Dr and follow through with recommendations from there and please remember there is absolutely nothing wrong with medicating paranoia if Dr's prescribe meds. Just as you would take heart and cholesterol meds so should you or anyone else for mental health.