I think its a mix of genetics and stress that has caused your stuttering. The body goes through a ridiculous amount of stress during covid( in order to fight the virus) and it kind of creates a traumatic situation for the brain which may have led to the onset of stuttering. I can vouch for this for my stuttering has become progressively worse since i got covid. If I were you, I would seek a mental health professional first and then see, if the stutter stabilizes( it won't go away) to a minimum amount.