Latency issue.

Hey, I love Aternos and how great it is! Normally, it would be a bit slow at first but eventually everyone's ping would get better, but today, the server was slowing down instead of speeding up. I started my server about 1 and a half hours ago, and when everyone joined, only one had enough chunks loading to be able to see. We had to all teleport to him, and no one could eat, break, place, go through portals, chat, or even really do anything without having to be patient for about 10 minutes. This server is a SMP, fully vanilla, and there are 5 people online right now. The chunks can load now, but it's still impossible to really do anything properly. My ping is in the range of 170-180 and it's not improving. Is there a way to fix this? I asked everyone if they have lag machines and they responded that they didn't. There's nothing that should be in the way of the server running faster, yet everyone's still not doing so well.