Job(less) Stress

I just got a phone call about a job. I'm still kind of wandering around waking up however and wasn't expecting any calls (I thought it was my bf calling) so I was caught totally off guard and don't think I came across great. I basically told him I hadn't done the job he was looking for before (which I hadn't in title but I know I can do!) and consigned myself to a lower position if anything. I feel like an idiot.