There are many lemmy instances in the world, but currently most people are using lemmy.world. This is why everything has gotten so slow.
You don’t have to delete your lemmy.world account, but check out https://lemmy.fediverse.observer/map it’s a geo-based map of lemmy instances – explore stuff nearest you, pick one, sign up, search , subscribe and begin interacting with your favorite communities. It’s easy, free and it will be faster. Try it!
I am planning on moving to lemmy.blahaj.zone soon-ish but I have 2 questions.
How do I move to another instance?
Can I move freely? For example, could I switch to lemmy.blahaj.zone to lemmy.world to kbin.social every day? I don;t like the idea of being “tied down” to an instance for a long time.
As far as I know, account migration from one instance to another is currently not possible on kbin/lemmy but with the sudden influx of users and developers I believe it is on the roadmap for at least kbin and likely lemmy too. For now you’ll have to use multiple accounts, but eventually you should be able to migrate if you choose to.