Move to a new, smaller, instance. You can still use lemmy.world as though it was still running at full speed. You can still post to lemmy.world or other federated communities and you experience won’t be so painful.
Lemmy.world is experiencing an influx of Redditors and with us good Redditors come our awful trolls. Growth, along with DDoS attacks have plagued the site since I began using it.