This feeling, the point of your title, comes in waves it would seem for me. Not all the time but I feel it. Sometimes it lasts for a short while, minutes if you will and those times are a great time to mentally regroup and figure out what was causing so much distress. As per advice. This is going to sound "corny" being yourself is the only idea I have. Your stutter isn't worthy of your stress or the shame you feel. You aren't just a stutterer. And you have merit and worth that exceeds a single "thing."