TLDR: Sorry to hear you're having trouble! Apple VPNs sometimes get stuck in a "bad state" which blocks internet. The best way is to uninstall Opal and reinstall.
We are aware of an issue where Opal's VPN gets into a bad state and and internet connection can stop working.
You may be affected by the issue if you see the following:
What to do about it.
Unfortunately this issue is on Apple's side, and the only remedy we know is to reinstall Opal entirely.