I doubt yelling was the cause of your throat infection. It probably got infected because you were tired and run down and your immune system was low, due to lack of sleep as your studying for exams, as well as probably not exercising and eating normally.
You shouldn't have given up. EP's is only 2-3 weeks of your life. They were right in saying it makes no different what aircraft type you're on when conducting emergency procedures training. It is all very similar. Did you try gargling and drinking lots of water and taking throat soothers. Or even try warming up your throat.
To be honest with you aswell, regional airline commands are easier as there is only 1 main door and there are no slides so they actually use less commands.
I'd also like to point out there are more commands on a jet aircraft as apposed to a regional aircraft. The jets have primary cabin crew members, secondary cabin crew members and assist cabin crew members, plus also there are land emergency commands and ditching commands with and without slides and rafts. Regionals just have one set of stairs.
Maybe try searching some some aircraft emergency landings or even watch some movies or documentrys. That would also show you what crew do inflight.