Speaking slowly really does help. I find that when I speak slowly, I worry the person I'm talking to is getting annoyed, so I start speaking quicker and end up stuttering as well. They probably don't even notice I'm speaking slower in the first place. I know some people who genuinely only stutter under times of stress. Maybe your illness was causing you to feel more stressed out than normal? Once you feel better, it might not be an issue. We can hope, anyway!