Wow, I could had written that in my 20s. You are right, acepting it is very hard; specially for people with those traits you mention. However the work is not only controlling your negative thoughts, it is also transforming that person you want to be in your head. For me when that person and myself doens't match, I felt ashamed of who I was and my stutter and axiety skyrocket. It's not lowering your expectation, you can do whatever you want; but your image of yourself should be realistic or sooner or later controlling all those negative thoughts will become too hard. It's something a bit difficult to explain, I hope it's more or less clear. Good luck with your speech therapist and psychologist, I hope you the best!