That's the way it should be - you avoid society, so you've developed this defensive reaction when you step outside your comfort zone. Instead, I suggest you get into a multi-hour discussion with someone. Or enroll in a foreign language class, philosophy class, and so on. Don't shut up during the conversations, going off on your own, ask whatever pops into your head. For the first 15 minutes you will be nervous, stammering, trembling, but what next? Then you'll have no choice but to speak calmly and measuredly, stuttering only in the slightest, because the longer you are away from your familiar environment, the more unusual it is, the more new horizons open up, the more your perception and your capabilities expand. And again, during the conversation, focus on the conversation, not the stuttering, don't shut yourself and your thoughts down, be actively engaged. And yes, I know how that sounds. It seems like an insurmountable task to you. But if you want to get rid of stuttering, challenging yourself to face your fears rather than running away from them and letting them grow is the only way out.