Samsung Galaxy S3 — Did an update and my phone flipped out

Is something going on with a bad firmware update? I updated my phone this afternoon and my galaxy s3 started freezing real bad. Almost like a computer with low memory. Everything was ok before I updated. I called tech support and they said I was the only call they received and said I should go to a sprint store. I went to the sprint store and he said I needed a factory flash reset. I had him do one and lost everything apps, pictures etc. For some reason my phone will not download apps now! Not a happy android camper right now.