Anonymous wrote:If it keeps bugging you contact your employee assistance program to make a few appointments with a therapist to work through it.
New poster, came to say exactly this to the OP.
OP, it sounds like there are actually larger issues at play for you, totally apart from this guy and this email -- issues you admit you've been experiencing, like social issues since Covid isolation, getting older, etc. It's all right there in your post. Please talk to someone professional and objective! This sad, sick man's breakdown is causing collateral damage in you, but the issues you mention are ones about which many of us are concerned. If you don't have an EAP or don't want to use an EAP if there is one, get some counseling or therapy to work through this. It doesn't have to be years of therapy, just enough to get you back on an even keel after he knocked you sideways. Remember, you are getting help to talk about things you knew were in your mind before he wrote that email--this isn't really about him or his words at all.
I get it, OP. Like others here, I have a relative with mental illness who has at times written letters containing total fabrications of negative things I've said and done. No matter how much any of us says, "That's not true" to ourselves, it can still sting and cause us to doubt ourselves; that's just a normal human response, I think.
You are not alone in being this guy's target at your office; others reached out quickly to you out of concern for you, too, which is a GREAT positive on which you can focus.