Actually, in my opinion, this "nightmare" trip description is quite typical for most Supplemental Carriers flying International operations... just not all of these disasters on the same trip sequence! Geeezzz....
However, I would have to ask the question - If you are on rest, then why are you checking your schedule so often? It would be scheduling's responsibility to notify you of any recent changes to your schedule, and you really wouldn't have to be so readily available to take any calls whatsoever during your rest period. I understand being a new-hire and all that, but it appears that you were just new to Southern, but not a newbie to the industry...
And, you were lucky to have your luggage catch up to you! Sounds like you'll be encountering more of these horrible trips in the future... so good luck, you're going to need it.