I'm the same way, sometimes I go months where my stutter is not too bad and other months where it would be really bad and I can't even say one sentence clearly. Don't be too hard on yourself. Anxiety definitely makes it worse for me. I went to speech therapy for a few years and it didn't really help tbh. Their main tips were to speak slowly, which doesn't exactly help. For me what actually helps is if I say what I'm going to say in my head before I say it aloud, and to take your time when saying it. It's also good to remind yourself people don't think about it as much as you are in your head.