Hello Carol,
We are sorry to hear that you are experiencing site slowness after some hosting account changes made to accommodate minimum requirements for our plugin.
If the admin notice is not going away, then there is reason to believe the server is still not on a recent enough version. If that’s the case, you also won’t see a “Contact Form” admin menu item on the left, with our logo as an icon. Until for sure though, we will leave the possibility open that you are seeing the menu item and the admin notice is not disappearing quite yet.
Hard to say what may be causing the slowness after the update. Could be one of any or many sources from your install. It could also be a possible misconfiguration with the new version causing performance degradation, which may be the case given the admin notice not going away. Would not hurt to contact the support team for your hosting provider to see if they can pinpoint possible sources and help confirm that the PHP upgrade was completed.
Hopefully we can work through this and get everything running smoothly again for you.
Let us know if you have any questions or if your hosting support came up with anything, if you contact them.