I ventured to the link with pics of your "rear-ended-ness". Horrible.
My friend, seek a specialist and have your spine and neck(especially) looked into. Sometimes it can take months, or even years, for either of these types of injuries to rear it's ugly head(s).
Did this person run into your trailer chock full of your livelihood? No equipment were damaged? He didn't end up in the same spot as your mower "was"?
The man who can smile when things go wrong has thought of someone else he can blame it on.