Like others said your parents know something is going on, they don't know what unless you share this with them. Knowing there is something tangible they can do for you, like taking you to a specialist doctor is a relief.

What will a psychologist do? Talk to you and determine what the best treatment is for you, talk therapy, medicine, a combination, maybe finding an activity for you to connect with peers.

This is medical so no one would need to know as you are covered by medical confidentiality laws unless you or your parents shared it. If you don't want it shared tell your parents you want to decide who knows what.