Hi mikey boy,
Good to read you are moving forward and keeping my fingers crossed for you to catch the right dentist as soon as possible.
Any practice who is willing to work with nervous patients will understand that it‘s all about trust and about chemistry and also that appearance can trigger so they should be happy to let you see a particular dentist if you wish so (unless it‘s a specialist who only does particular treatments). They should be also happy to allow you to see just this dentist for all your treatment (again if there is nothing you need a specialist for).
If a practice doesn‘t make this possible, they do not value personal approach much and you should keep on searching.
I know asking questions and making demands can be hard especially in the early stages of dealing with a new practice, but learning about how they work in advance and asking questions may prevent you from playing worst case scenarios in your head..
Have you scheduled already?