I understand you felling bad been there!So has most all bowhunters including myself.
Its not something we want to happen but it does!

I guess one of the biggest things that i have learnd from deer i have lost due to bad shot placement bad judgement,ect is that now when i get ready for a shot that i am about to make, I remember the deer i have lost and what caused it and i try not to make the same mistake.

PS,You will be ok! And i would be willing to bet so will the deer!
This experience will only make you a better hunter if you can learn from it.