Answer:
The answer is social anxiety disorder (SAD), more specifically the performance type.
Step-by-step explanation:
Social anxiety disorder is characterised by fear of engaging in social situations for fear of being judged or ridiculed. People with SAD might experience strong physical symtpoms such as nausea and even fainting.
In the example, Patrick suffers from performance type of SAD, as he is only anxious while performing live. A person with general SAD would also feel reluctant to rehearse in a safer environment.