Convention worries and more paradoxes

I’ve been feeling down of late. A large part of it, is that a couple of conventions are looming and I’m getting worried that I haven’t got anything to submit to editors, or have read all the relevant books beforehand. I realise that I may be the only person who thinks like this. I have not signed up for any sessions for pitching anything, or having to interview anybody. I am not going to have to take an exam, when I get there, so I should not have to worry.

Trying to work on idea for a story, I’m having a problem with the Grandfather paradox. You can’t kill your own grandfather, but your grandchild could kill you, after you have caused it to be born. There should be a reason, for why this can’t work, but I can’t think of it.