Welcome to the community and thanks for posting. I'm very sorry to hear all your apps have disappeared off the TiVo®. I've not see this happen before but it's clearly a problem.
I've managed to locate your account to get the signals sent down again. I don't think this is going to work but it's worth a go. You'll need to restart the box once more and check if the apps have loaded.
If this fails then it's going to need an engineer visit to the property to investigate further. If they come to the conclusion the box needs to be changed then this will result in you losing all the recordings. Let's hope we can get it working before that though.