I'm sorry you are discouraged, if it helps, (and I'm sure I speak for everyone here)
We've all been there.
As others have said; good days, bad days. When the bad days start to outweigh the good, then it's definitely time to dust off the resume. Keep in mind that the grass is always greener on the other side of the fence too LOL
It NEVER hurts to look around as long as it's done descretely. As you are a student, if this is an internship; the EC is sorely mistaken. It is his job to mentor you, (personal opinion) it's why he has interns (although the labor is of course a bonus)
Depending on where you are, summers are stressful. Transient workers, tourists, long hours, heat, humidity and vendors that don't care that it's 14:00 on a Friday and you needed to start prepping for service early morning... sigh. We're all ready to kill each other here too.
Honestly, I wouldn't take it personally. Finding someone asleep on the job when the kitchen is getting their asses handed to them is reason enough to make a general announcement that everyone is expendable.
So back to the interviewing process; great answers have already been given, but I would also ask,
'what are your expectations of me'
'do you promote within'
'how long has the current brigade been here'
'how often are reviews made' (not necessarily financial, but skill set as well. You can't perform well if you don't know what the expectations are and don't have a yardstick)
'is this a new position or filling one that became open' (followed by, how long the other employee was there presuming that someone left)
Good luck! Stiff upper lip....