Symptoms such as chest pain, shortness of breath, palpitations, dizziness, fainting, and weakness should not be automatically attributed to anxiety and require evaluation by a doctor for a possible cardiac disorder.
It is possible you have a congenital heart problem that is now becoming an issue such as a valve insufficiency due to structual anomoly. Sometimes there is a hole in the wall that separates chambers, etc. worst case scenarios. See a doctor to rule out any heart problems. Take care
It seems to me that you have frequent attacks of irregular heart beats. You need to start a work up with a cardiologist who would ask for blood tests to exclude or diagnose the reasons of these attacks like anemia and hyperthyroidism. 24 hours ECG is the best way to diagnose the presence or absence of these irregular beats. Ladies of your age are the commonest to develop such attacks, and the cause could be related to the heart. It is wise to exclude any cardiac cause so you won’t feel any additional anxiety.