I'm worried about something and I hope that it isn't a dumb question.

I recently went to the psychologist and then I asked them to sing me up for therapy because I felt like I needed it. I think I might be ill, something related to anxiety, but the psychologist and therapist acted like I only have problems with shyness. My therapist told me I should smile more, that I should talk to people, start liking myself and don't stress that much, but I didn't find that helpful at all.

Is it possible that she is wrong about me and that I'm actually mentally ill? Do therapists diagnose people or was I supposed to go to someone else? Is it too early to worry about this?

I'm completely new to all that stuff, I've had issues with 'shyness' since elementary school but everybody always kept telling me I would grow out of it. Now I'm in high school, I'm going to be an adult soon and I don't know how to deal with this. It's not like I want to be diagnosed with anything serious but I'm really worried that I'm wasting time and only getting worse.

(I'm also sorry for any grammar mistakes, I'm still learning)