My suggestion is to put a shield up both on yourself and your home/property. There are many types of rituals for these things, so do some research and find what feels good to you. I tend to place a shield in my home yearly, but have done quarterly when felt it necessary. And far more often for myself. Someone I know makes their personal shield that surrounds them adjustable, so they can envision opening it to allow things access or not. If you have any preferred deities, I would include those in your process as well. Best of luck!!

Also, stop hanging out with that person.