That name block thing is really common with stuttering, especially when there's no backup word you can substitute. One thing people miss is that working with a therapist who gets the psychological side of stuttering (not just the mechanics) can make a huge difference, because it's often the anticipation and pressure that trips you up more than the actual word. I've seen people have good results with Better Speech since they match you with therapists who specialize in stuttering specifically and understand that whole anxiety component. also I'm sorry about the tumor, that's a lot to deal with on top of eveything else.