Much like planting a tree, the ideal time to use your own domain for email was many years ago, but the next best time to do it is today.

Do it! minraws.com (if that means anything to you) is available, you could be firstname@minraws.com as well as your @gmail.com before the sun goes down. Personally, I'd set it up to feed into a new mailbox with Protonmail, but if you like you can just have it forward to the familiar gmail inbox you're used to.

You can start moving your accounts over one at a time. It doesn't have to be instant. Yeah, there are probably IRL business cards in drawers and people you haven't contacted in decades that will mean that you want to forward all emails that go to your gmail to a folder/label in your new email domain forever, but that's OK.

Just start.

Already have one but moving old services especially banks, and licenses and very old accounts and so on is such a PITA. I had to fill a dozen forms to move one of my govt accounts to my new email. This is not fun..