Re: Feeling horrible after doing a tarot reading :'(
Well, since this is solved we hope we know the answer. I am still going to chime in because I am just that cool (I am really not that cool).
Many factors can go into this, including the deck itself you use, the connection between you and the target you are reading for, or even the deck to that person and subsequently to you.
Any time you are doing a reading, there must be some connection (which is why I am so painfully and fervently skeptical to the point of completely disbelieving in "online" readings).
Shielding can be important, some people who don't know what it is shield naturally, it is something that can very well be reflexive or innate (especially in my opinion, to incarnate Angels), however when focused it becomes better organized and focused, therefore more effective.
In the future, whenever you do a reading, I always suggest cleansing and disconnecting from the target of the reading as well as the deck, just to make sure it is all fine and clean and dandy for all.
The maximum effective range of an excuse is zero meters.