When I feel like this, the only thing to do is get out there, even if it's for 10 minutes. otherwise it becomes a big mental barrier. If you haven't been in 2 weeks, why go now, because it'll hurt etc., But it'll be harder to get out the longer the break becomes. Running is, to some degree, a mental thing and you just need to clear you head of the excuses and issues that are causing you to put off running.
I find that I need to have targets lined up, so I book the next race before I do this one, so that there's always one booked to do. And yes, I have started running, from scratch, more than once, so I know what I'm on about!
Alternatively, I remember a piece of advice I read on here (a very long time ago) which went along the line of "just get out there, you big jessie". A more amusing version of HTFU, but the same sentiment.