Tired so I stutter and so stuttering makes me tired and the cycle continues

Tired so I stutter and so stuttering makes me tired and the cycle continues Lately I've been doing work that really uses my brain and I'm SO mentally drained. I've asked other people who do the same work if their head hurts but apparently not. Only me. Either way, I'm tired from working and so I stutter. Stuttering makes me tired. It's really feels like I'm trapped. My Vitamin D and iron levels are low so there's that too. But I am very sensitive and get tired so easily. Probably don't do enough exercise either. I'm tired of life.