Daugther with emotional blockage...how to help ?

Hello. I am looking for help for my 18-year-old daughter who has been suffering from emotional disorders for a year. Exactly a year ago she had Covid and about 2 months after being sick, she started having dizziness and panic attacks to the point that she was afraid to leave the house. Additionally, I must add that for a long time she also had a lot of stress related to the end of high school. I dont know to what extent these events had an impact on her psyche, but I think that her character also had an impact. Since she was a small child, has been very shy and couldnt show emotions. She accumulated all her emotions inside. She never cried. She is a crazy perfectionist and demands a lot from herself. He gets very upset when he makes a mistake. I think that all these emotions have accumulated in her and now they have reached their zenith. I would really like to help her because I can see that she is struggling a lot. I talk to her a lot and also talk to a psychologist, but so far to no avail. What bothers her most is that she is constantly agitated, dizzy and feels constant stress around her heart and stomach. Does anyone have experience of how to help in such a case? I will be grateful for any advice.