Ouch, sad to read this story.
We all had check ride "nerves".
I have never busted a sim ride after 7 different airlines but some have been closer than others. Found my own "solution" : Overstudy, read way deep and know every checklist, every call out, every profile by hearth, then do it again. This will give you plenty confidence so you won't get rattled when heat is on.
(My first jet was right seat DC-8-73 for Evergreen, tough course, tough airplane, old sh!tty simulators, no experience, mean check-airman..
Made it on the first try but it was the longest morning of my life. Learned to study harder after that gig )