I have confirmed the problems are server related - it's quite overloaded right now.
I have managed to arrange a move to a new server that is being built right now, hopefully within the next 24 hours or so the site should be moved and performance should improve.
Note that there may be a period where the site doesn't work correctly and you see error messages - that will be due to missing software on the new server that I need to request my provider to install ... I'll get that done as soon as possible after the migration.