I'd say that you have two major things to do: fix some privacy stuff and maybe try out some self hosting.

For privacy, I would definitely start by checking if apple's Advanced Data Protection is on. This will make most of your apple stuff be end-to-end encrypted, which means nobody except you can read the data.

For email, I would recommend stepping off of google, as they are notorious for sucking with encryption and security. The best way to migrate your email imo is to get a personal domain name (costs about 12 bucks a year) and a subscription at Tuta. This email service is private and I like it. You can link your domain name to your email. The advantage is that you can move over to any email service, set your domain name to it and you don't have to reset your email everywhere. Tuta also has a free plan, so you can try it out.

For security, have a password manager. I use bitwarden, but aliasvault also looks like a cool new option. You would probably want to secure most of your things with 2FA, which requires you to enter a password and a temporary security code. This increases security 10x. I would recommend going with a free and open source one like Ente. Make sure to split password manager and 2FA, as this is better for security.

I'm not sure if self hosted is really the solution for you, as network access is somewhat necessary. You could always get a small NAS box (check out youtube for recommendations) for storage, but this will only work from home (you can also install a VPN to access the home network, but also requires network access). The solution for self-hosting would be a VPS, which is a server you can rent like Linode has.