Antivirus

There are no viruses that can affect an iPhone (unless you jailbreak it). So, no anti-virus programs are necessary. If your iPhone wasn't jailbroken, what you got from Messenger was a scam attempt, not a virus.

They are used to access secure servers. Unless your employer is providing you with a VPN, you don't need one. Subscribing to a VPN means that whatever company you have the subscription with has access to information on every website you access.

I'm glad it helped. This has been an anxiety-inducing year for most of us. And I've found I get anxious about everything, not just the big "real" things.