Last I’d heard, even the NSA hasn’t been able to find an encryption that is quantum safe. And the some of the one they had found were broken using traditional computers. I strongly suspect that your messages will remain reasonably private for at least the next decade or two.
That sounds like an overloaded server. If you not willing to put up your own server, you might try a few of the smaller public instances.
There is only so much traffic the larger instances can handle, and right now it seems like everyone and every community is on only a handful.