I just checked your account. You're using 1.13
1.13 is very very bad in performance since Mojang made huge changes in the way how minecraft stores world data etc.
We can not really change that. We already tried to enhance the performance by increasing cpu and ram resources for it. But at some point it does not really help to make it better.
We can only hope that Mojang will release newer versions with better performance soon.
Ok, thanks for the information. I'll keep checking in and see if it's fixed.