I really wish I could suggest something - but my stutter isn't anywhere near severe and it's only started recently at the age of 14 due to having social anxiety. I really understand your point though about only contributing little to your friends conversations... even though you know they'd understand. I'm always worried about being around my friends now, as even though I have plenty to say, I feel like they zone out or get bored alot of the time. Anyone could easily say I should get better friends but in all honesty I don't blame them for getting bored. I stumble alot on words and even the slightest stumble or block embarrasses me alot so I can't even begin to imagine how you feel. The reason I say "I wish I could suggest something" is because you mentioned you've stuttered your whole life. There isn't much I can say or suggest that you wouldn't already know yourself. All I can say is to wish you well and hope your happiness improves over time :)