Thanks so much for all your thoughts. To answer your queries, no it's not a stinging feeling, more of an ichiness that becomes really sore and kind of burning. It comes and goes though, but I can't work out if it's related to anything like soap or something. I didn't tear or have an episiotomy either so I can't blame it on that (though things definately got rather battered up regardless!)
It sounds like I'd better get it checked out properly but in the meantime I'll definately try the canesten or hydrozole cream. ...So many nasties that we can end up with!!