Break it down to manageable chunks. I've worked on quite a few large scale projects, and when broken down, any part is usually something you've done before. But yeah, the first few of these large projects were scary as hell.
It's like eating an elephant, one bite at a time.

Usually MMORPG's (WoW, Elder Scrolls Online, etc.). Recently I've gotten into Star Citizen.

@AvatarOfKaine saw the other comments and thought the negativity had to be countered.

No idea who you are. But a stranger is just a friend you haven't met, so; maybe in time?

@Demolishun but it's one hell of a continuous kick to other people's groins until then.

On principle I'm with you here.

Do a fair bit of work with MS Power Apps for clients though. Anything not 2xx is swallowed in the "developers only" diagnostic. Sadly have to send everything the "wrong way" for users to be able to report issues.

@platypus well, my predecessor was offered help to find another job. I think the main reason for the consultants reaction is that he very much feel responsible. And my explanation is pretty close to your suggestion.

I have 25+ years in dev. Will let you know.