While I don't have anxiety about my hair like you, I do have terrible anxiety when it comes to dentists. I have to get my wisdom teeth removed soon. Luckily the surgeon is going to give me general anesthesia. However I'm still freaking out about it. I really hate people messing around in my mouth. For me there's really nothing I can do about it except do some deep breathing/meditation before I go to a dentist. It might be too late for this, but another thing you can do is research. Look up customer reviews, and go to higher end salons. It will be more expensive, but they usually hire people with more experience. Also, TALK to them. Don't be afraid to tell them exactly what you want, and if you're not happy about something when they're done, TELL them. They might be able to do something that you'll like better.