that my hobbies are collecting retro video games, watching 80s-early 2000s anime, and the like
I can promise you that you’re not the only human in your area that is interested in these things. Sounds almost main-stream to be honest. You do need to find a place where you can share your hobbies with others (conventions, gaming groups, fan clubs). Without meeting humans there is little chance to meet interesting humans (serendipity). I‘m not only talking about finding „the girlfriend“, but also friends in general.
Should I just give up? At times I feel like life and everything that comes with it is pointless, that it’s not even worth it.
Certainly not. You already realized that you want to change your situation; that’s a good first step already. Now talk to new people. It doesn’t matter where or who. Look for hobby meetups in your area and go there. You can also learn new hobbies. Join a choir or cake connoisseur championship for all I care; just don’t do it alone if you’re feeling low currently. We as a species are social beings and need social contacts. There are groups and clubs for everything.
Or it might indicate that you‘re somewhat gullible and consume too much propaganda.