Severe, sometimes almost to the point of calling it a disability. My stuttering has ruined many things for me. Sure, I have a learning disability, avoidant personality disorder, PTSD and OCD, all of which have made my life hard but I genuinely think that If I would not stutter my life would have been a little better and easier. My stuttering is the main reason why I have never had a proper relationship, I simply don't trust people to NOT laugh at my stuttering or think that I'm stupid because of it. I have had very bad and traumatizing experiences with other people so I generally don't trust them at all (especially men) and almost always expect them to be either ignorant, selfish or plain evil. Because of this it's always surprising to me when I meet someone who is genuinely a nice person and doesn't treat me (or others) like trash because of my speech problem.