When ever my stutter is worse then usual. I take ten minutes a day to meditate. Just sit somewhere quiet and focus on breathing slowly and relaxing. It definitely helps my anxiety levels in generally and makes me more fluent. If I'm entering into any conversation where I feel a bit tense. I have a couple of strategies. I think to me self. "in 5 minutes I'll have made the call. Got what I needed and it won't really have mattered if i stuttered or not in the big scheme of things." just gotta get through those five minutes. Your day can be 100 five minute periods if you need it to be. I also have a a well rehearsed "hi how are you?" and wait for them to answer. It turns the conversation from a transactional one to a personal one. This defuses alot of tension for me and make me stutter less. The more you do it. The more Confident you'll get and the less you'll stutter too.