Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency help for thoughts of suicide with an intention or plan, an inability to stay safe, severe chest pain, fainting, major breathing difficulty, or signs of a possible stroke or other medical emergency.
In the United States, call or text 988 for the Suicide & Crisis Lifeline.
Call local emergency services when immediate medical care is needed.
Contact a clinician promptly if anxiety suddenly becomes much worse, you are unable to complete basic daily activities, you are using increasing amounts of alcohol or sedating substances, or you develop concerning symptoms after starting or changing a medicine.
Routine follow-up helps a clinician assess symptom changes, side effects, sleep, daily functioning, and progress toward treatment goals.
Early follow-up may be more frequent when starting therapy, changing medication, or managing significant symptoms.
Once symptoms are stable, visits may be less frequent.
The article also says
Tell your clinician if treatment is not helping, side effects are difficult, or avoidance is increasing.
A different therapy approach, medication adjustment, or assessment for another condition may be appropriate.
Recurrence does not mean that treatment has failed; previously learned skills and early support may help.
Every sign above is quoted from the sofidex article on Anxiety & panic. If you are not sure, err upward — it is always reasonable to be checked.