I had visions of nailing boards to my head to prevent creatures from contaminating my thoughts... then in a moment of sheer brilliance I figured that just keeping my mouth shut would deal with 90% of thought leaks...
The thought contamination / implanting needed something less strange to attract less attention. I just couldn't come up with a design that worked, and motorbike helmets were completely useless. I figured how antipsychotics worked - they dulled the mind so much that nothing could be thought anyway. Its kind of like making a host inhospitable to a pathogen. So I decided to not think in words - just visions. It sort of worked most of the time. The down side was I then had difficulty talking and writing.

Boarding up the doors isn't something I have done lately. Our windows are full of cottage panes and there are no burglar bars. I lock doors religiously, but it is all false security. For me the threats have all been a lot more nebulous than physical break-ins.

I hope you manage to find something that helps you feel more secure.