So I remember years back when fallout got removed from GOG. And I also remember buying up the classic ones I wanted. I have had almost every classic game I grew up with, for some time now. And I remember playing fallout.

But for some reason or another, fallout classic is not in my library anymore? The tactics game, i may not have bought that. But I know for a fact that I had fallout classic. I have fallout 2 classic, and I never played fallout 2 growing up. So I know I purchased fallout 1 classic. I would not have skipped such a huge part of my pc gaming as a teenager.

There is something wonky going on, I even checked my receipts and i purchased fallout 2 in late 2011. I was collecting my childhood games, and I would never have skipped over one of my favorites. I really feel like something got messed up.

Has anyone else had issues like this before? Do I need to start keeping track of every game I purchase and save emails so they dont get taken away?

It happens from time to time that games disappear from people's accounts.

https://www.gog.com/forum/general/im_missing_several_games_homeworld_remastered_x4_foundations/post1

Contact support.

And for your last question: absolutely.

I've been doing this since I got here.

Yeah I should have been apparently. I already searched my email, and my bank only gives me the option to go back 2 years to check the past purchases. Maybe I can contact them and get records from that long ago, but there is no garauntee.

https://www.gog.com/forum/general/gog_if_you_want_to_attract_new_customers/post154 Everyone should archive every order confirmation e-mail, print every receipt on the orders page as PDF, and have some kind of proof of purchase. For gifted items, I copy all that's visible on the orders page into a text file (since only the buyer can see the order receipt). I archive monthly bank statements.

Well, yes - of course!

Apart from that, I highly recommend creating a spreadsheet for your GOG games.
Just make sure that you take over GOG's nomenclature: trust me - makes things way easier in the long run.
Simply sort your shelf alphabetically, write down all your games in a spreadsheet, using the names GOG has given them(!)
Afterwards you can change the sorting filter on your shelf to whatever you prefer, of course.

With that spreadsheet (assumed you keep it up-to-date) you can always quick and easy check whether the number of your purchased games is still the same.

If your spreadsheet shows a total of games of 1234, but your shelf only accounts for 1230 games...you know immediately, something is wrong and can look it up.
Put your (alphabetically sorted, again) shelf besides your alphabetically sorted spreadsheet - et voila: any change is easily to notice.

One thing though: games that you "hide" don't count towards the total number of games on the shelf - keep that in mind and check first whether you have hidden something lately, that you haven't taken out of your spreadsheet yet, when you notice something amiss.

I have my hidden games separately listed under my "visibly present on the shelf" games - that way, the total number for both (visible and hidden) is always correct.