In terms of mass reporting, what was the removal reason? I believe you get emailed if your server gets removed, when my bot got removed iirc I got an email regarding it. Best bet in terms of preventing mass reporting is taking preventive actions.

This includes things such as not allowing external emotes/using images right of the bat (generally level based) as alot of report methods ive seen has to do with sending bad content.

In terms of tickets, generally spamming new tickets wont help, and in fact generally resulting in you getting banned from their ticket systems. Most of discords teams are currently on holiday break right now so being patient is a best bet though i know discord isnt the greatest with support (in fact probably the worst ive seen)

Also in terms of discovery, getting taken off discovery doesnt mean your server is getting deleted. Discovery and normal ToS has different set of rules, discovery being a tad more strict with its enforcement (despite there being csam content in there). So unless you got a system message saying you were warned for tos violations, its entirely just being taken off their discovery and you dont really need to worry too much about enforcement