How do you deal with someone trying to call you "Stolen Valor"?

Tell them to F off. You do not have to prove your veteran status to any idiot that decides to confront you.

You are asking what you should do about something that hasn't happened. So far, it appears this is only in your own mind (guilty conscience?).
It you are or have been evaluated medically, then you have served and should have nothing to worry about...unless it was something self-inflicted, which I doubt.
Until and unless someone in authority challenges your use of the parking spot, I wouldn't worry about potential problems from other people. If questioned officially, your VA Card should be proof enough.

The proofs in the pudding. Our best signatures are our dogtags, VA Card and our DD-214. I've been told on several occasions that I was a Stolen Valor veteran even with proof that I served our great nation. But those who are accusing us didn't serve and blame a fraction on their body as the reason why they couldn't serve. Dammit, I served with flat feet which is now one of my service connections.

Whatever you say and walk away. The burden of proof is on them and not you. Most of the people who make allegations are "want-a-bes".

Forrest Gump said it about as good as anyone can...... YOU CAN'T FIX STUPID! Ignore them and walk away!

YOU KNOW WHO YOU ARE AND WHAT YOU HAVE DONE FOR OUR COUNTRY, THAT IS ENOUGH. YOU DEFENDED YOUR COUNTRY AGAINST OUR ENEMIES, YOU NEED NOT "DEFEND" YOUR REASONS.

I would turn my back to them and walk away. I do not owe the Dipshidiots an explanation. I have done just that a few times after I look at my H/C Disabled Veteran license plate on my car…..

I’ve been asked about being in ACU pants walking into Walmart. College age kid (college town) walked up and started asking me about my service while his gf was bringing her phone up. He asked y MOS, so I replied to him as I have at the VA, gave him my MOS code. Saw the blank look and smiled and just rattled off units and stationed until his eyes glazed over and told him to have a nice day. He busts out a sorry as I walked away. It’s a pity that everyone is looking for stolen valor and wants to call someone out.

First off I do not Believe you will have any issues, But! if you do run Into that Individual or Individuals, who are looking to make themselves and you famous on the Internet, sadly they are out there , I would Just Tell them Very Politely if they have Any Concerns they can take it up with Management, Why Management? I would never show a Stranger My Driver Licenses, VA Card, or Retirement ID Card, this Individual could be looking for your Address, or other sensitive information, that on your ID. my Motto is , Don't trust anyone, that has not earn it. Stay Alert, Stay alive , they could be using the Stolen Valor as a ruse to get information, in order to Rob you. I have had Individuals try to engage me into a heated Discussion over me Parking in a Handicap Spot, even though I am 100% Disable, and Have the Proper tags and Handicap plaque, I Completely Ignore them, make every effort not to engage in Conversation, If I say anything at all, I tell them to call the Local PD On the Non Emergency Hotline to have me ticked or towed, I know that not going to happen, all that happens is Local PD Arrives and educates the Busybody Citizen and tells them to leave me a loan, or if they are very aggressive, next time they will be arrested. My Point is Make Every Effort Not to Engage these Busy Body , these Karen's who are looking to make themselves feel important and famous on the Internet. they will only get you Hurt, Arrested, or Rob.

I don’t. I know who and what I have done! Don’t need to prove anything to anyone!