That sucks, but it's great you told him off, even after stuttering. Shows a lot of self respect to do that, even when you're feeling like shit. I would look into therapy. Real therapy, not the pointless exercise stuff you might have done as a kid. If you live in the UK, check out the BSA (British stammering association). Again, it's totally ok to feel how your feeling right now; maybe you can use this pain to motivate yourself to do everything you can to improve. At the very least, a therapist should be able to help you work on the facial ticks and stuff which at the very least will make stuttering easier.