My concern is primarily that I already have this email address attached to a plethora of services, many of which I've even forgotten. I parted with an older email address many years ago when I was much younger, but now I'm faced with an account I've had for much longer, which is attached to many more important websites and software.
pwg|6 years ago
You'd be best advised to obtain a domain, once you have that then you have a fixed email address that you own (to the extent that you 'own' the domain, but as long as you pay the yearly fee [which can be paid up for ten years at one time], you effectively do 'own' it).
Then you can begin migrating things that are attached to gmail away from gmail and to the address you own. Eventually you'll have all the very important critical items migrated, and the ones you missed you may not feel so troubled to ignore.
As for email service, you can purchase email hosting (some services have been mentioned here already) or you can self host (which is what I do with my domain). Self hosting is not that hard, but it does require a certain level of internet and networking knowledge, which if you don't have could make attempting to self host feel like a nightmare. In my case, I've had the same email address since about 1999 or 2000 (I can't remember exactly when now). It has moved across four different internet links across three ISP's in the ensuing years, but never once was I ever at risk of losing any old emails because a 'provider' decided to close down or to arbitrarily terminate an account.