I don’t need all the stuff they offer.
I ONLY need email@mydomain.blah…
Anything out there thats free or self hosted just for this.
Porkbun is pretty decent but actually is 25 USD a year, and so same as a single Google workspace account.
Or self host email with a basic web email gui.
If you want to send mail from your custom domain from within Gmail, you need to use an SMTP relay like mailjet, mailgun, sendgrid, etc. Most have free tiers with high enough sending limits per month that are more than enough for personal use.
Once you have signed up and get your SMTP credentials, you can add it to Gmail like here: https://support.google.com/mail/answer/22370?hl=en#:~:text=Step 1%3A Add an address you own 1,username and password on that account. See More.
Your SMTP relay will also provide instructions to setup dkim/spf records with your dns.