PDF notes disapeared

I have been editing some pdf's for a few weeks, most of them where notes in class or during studying, I have an adobe.com account and I edit the pdf's on my iPad. I just discovered that everything I've been editing is gone. The pdf's are still there, but all my notes and marks are gone... I don't know how this happened, there is nothing wrong with my iPad and I didn't do anything. I just opened Adobe and a message came up that I wasn't connected to the internet and that I was logged out. When I logged in, I discovered they where gone. I am very annoyed by this and I don't think that I will keep using the adobe cloud if this isn't fixed... All my work of the past few weeks is gone... Can someone please help?

Thanks in advance,

Kelly