It's your Lemmy instance like lemmy.world dying under all the new reddit refugees.
You can't do anything about it but wait. It'll sort itself out once traffic has calmed down or the servers got boosted by the admins.
That was what I assuming as well, but it doesn't seem like I have the same issue on Jerboa. In fact, I can navigate much faster right now on Jerboa, even if lemmy.world is one of the slower instances.
Lemmy.world needs to move to an HA setup. Based on what I saw the server admin mentioning in his upgrade posts for this latest build I think he's just running a really big instance in Amazon and then using docker containers for every piece of Lemmy which is making the site very slow. To properly spread the load he needs to create individual servers for the individual pieces of Lemmy. Unfortunately if you're not a sysadmin this type of setup can be tricky and kind of hard to get going.
Ruud is one of the more qualified system administrators in this space technically speaking. He and a few other knowledgeable instance admins are having to invent solutions as they go because the biggest server was like 1/100 of the size of lemmy.world a month ago and Lemmy has not been optimized for this yet.