Unfortunately performance issues are not an quick or easy fix. It could be due to many, many reasons. Anything from your local ISP to your computer hardware to numerous things on our end. Every case is different (unless they aren't).
How can we get this figured out, you ask? Giving us a detailed report on our bug forums, with logs! This helps us look deeper into an issue and possibly establish patterns. If quite a few cases are the same, we can go "oh here's the issue" and start making a fix. We can't do this though without your help, though. Posting "my game crashed fix it" doesn't help us but those detailed game logs do!
I get that it's super frustrating, and I'm sorry that you're experiencing issues. I wish I could snap my fingers and fix it, but alas, that isn't possible. :disappointed: