Without knowing which area of history is your focus it's hard to give a specific answer, but for myself I've found that blogging is a great way to stay involved in academic study when I can't actually work in it. It lets me choose whether I want to be formal or informal or somewhere in between, and basically play with primary sources whenever I want.

This works for me because my area is fashion/decarts history, and there's a big community of amateur and professional historians and living historians in that field who blog. I prefer object-based study and primary sources, and there are a lot of primary sources and museum pieces online and easily accessible. I'm not sure if it will work for you, but there do seem to be plenty of history bloggers out there!

Google Scholar and Academia.edu are two public databases, but I'm not sure how helpful they are; I don't use them much.

Is there a university or large public library within reasonable travelling distance for you? Most have very affordable public membership schemes that give you at least reference access to their entire catalogue of books and hard-copy material; many also have access schemes that allow members of the public to use a selection of their digital resources (including in some cases journal archives like JSTOR or Project Muse). For individual researches, JSTOR now offers paid access to the majority of its back catalogue through a scheme called JPASS. It's pricey, but a subscription gets you access to 350+ History journals.

For identifying books relevant to your interests, searching JSTOR and Project Muse for reviews can be pretty useful, too. Even without access to either database, you can usually read an abstract or excerpt of book reviews that should give you a good idea of whether a particular piece of work is worth checking out or not. If your library doesn't stock a book you want, then you may be able to ask them to order a copy from another library for temporary use; for older works, AbeBooks sells second-hand and ex-library copies at rock-bottom prices and is definitely worth checking if you want to build a personal research library.

In terms of primary source material, in some fields you will find that a huge quantity of material has been digitised and is now readily available. The University of KwaZulu Natal for example has been digitising an immense quantity of archival material on South African history which anyone can access; the Digital Library of the Caribbean contains literally tens of thousands of publicly available documents, videos and photographs for anyone interested in Caribbean history.

Many physical archives welcome independent researchers and members of the public, too, if you can take the time and cost of traveling to them. Their staff are usually more than happy to help you if you've never used an archive before, or if you've forgotten how it all works.

Serious question, could this be considered meta?

In addition to the good advice from /u/sowser to see if your local university library offers a public membership, you might want to see if your period or area of interest has any large gatherings or conferences that you could attend. Some conferences are stuffy, but many can be very welcoming, and they give you a chance to hear what historians are working on right now instead of waiting for it to filter out of academia. I'm sure, if you let us know what country you're in and the period you love to study, someone here could point you toward a good annual conference to attend.

Academia.edu is a fantastic place to keep abreast of new publications in whichever field you're interested in - you can follow particular scholars or journals and receive email updates when new material is posted.