Yup- I know exactly what u mean. Looking back after a meltdown, you realise how trivial the issue really was.
If you are nervous to phone your pdoc, maybe first talk to your T. She may be able to help, and it may not be necessary to make a med adjustment at all.
Can you write your thoughts and feelings down in a mail? Can you send it to her beforehand? Otherwise print it out and take it with you. If you find you cannot bring yourself to talk about it, let her read it. You need to work through this, and she needs to know what you are battling with.
I'd say first make your T understand-they usually are the more empathetic ones, and let her help you deal with the issue. If she feels your pdoc needs to be involved, then you can make the decision together