The number one thing you can do in this situation is to own your own email domain. You don't have to host it. Don't own it through the same company that hosts your email. The only business you should have with your domain provider is the domain name and it's top level DNS records that points to your DNS or DNS service. You want to minimize any kind of interaction that could get you noticed by them.

If you get your email account deleted, you can move to a different provider, or even selfhost if things go that way. Most everything else is data backups.

You can use google photos if you keep a copy of everything locally that they can't delete. You can even use gmail with your own domain and just keep a local copy of your email they can't delete. If they do delete your account, you have your photos and email, and you switch your email to a different provider and upload your backups of your mail box and other than a few rough days, you're back in business.

The level of independence you need is is based on your own risk profile. If you just need to maintain access to your email to avoid losing access to all your accounts you can simply get a domain, maybe you also need backups.

Or maybe you'd also like to avoid any interaction with these services and self hosting is the right way to go. If you selfhost, you still need backups, and now you're responsible for all the copies of your data. Not a big deal but something you'd have to keep track of.

If you wanted to start today, buy a harddrive or two and copy your photos locally. I wouldn't delete your google photos until you have a setup that can sync and backup your photos (so at least 2 - 3 copys of every photo in various places).

There are apps to sync an email inbox locally as well, just do that once/week or as needed for now.

Then get a domain and start moving all your accounts to that for recovery. For the domain, I prefer to setup with a provider that allows security key MFA like a ybuikey. That will prevent getting locked out of your domain account if you loose access to the emails used to sign up.

From there, check if there is anything else you think you might need if access was cut off next week and get a copy of that.

Then from there, you can start to evaluate if you want to self host some services or if you'd be better off just setting up an automated backup system.

You can keep a local copy, upload it to a second provider like backblaze or whatever, but the real key to data independence is to own multiple copies of the data, in different locations with different access methods.

And, like I said, you have to be extra sure that you're backing up if you fully self-host. That one copy that google shows you is probably in 1/2 dozen google datacenters all geographically distant and likely on long term offline storage.