Brief Answer:
Performance anxiety is a learned anxiety.

Detailed Answer:
Hello thanks for asking

Sexual performance anxiety occurs in most individuals because of learning over the time. In most of individuals psychotherapeutic methods helps but that require a good psychologist and lot of patience.

To come out of anxiety you have to learn the basic psychopathology behind performance anxiety. You are 55, have high blood pressure. Some time due to age (compared to young adults) and associated high BP loss of erection occurs during sex. This loss of erection occurs at random times and without any significant organic basis. Stress adds up to this also. But this random erection causes loss of confidence and individuals start anticipating that if they will achieve good erection next time or not. This increases anxiety and stress unconsciously in mind. This anxiety and stress further deteriorate the erection and during sex poor erection is seen. So with time random loss of erections becomes regular loss of erections. This further cause loss of confidence and also increases the stress. Thus a vicious cycle with "loss of erection➡️ stress and anxiety➡️further deterioration" is formed. With time significant performance anxiety is seen.

So to come out of this problem you have to break this cycle. You have to improve your confidence and you have to convince yourself that there is nothing organic, you have no significant problems. Just because of anxiety you are losing the erection. Avoid anticipating that you will perform bad, and this will really improve your confidence.

I hope you are understanding what I am trying to tell you. You can consult a psychologist too for psychotherapy. Medicines can also help in making erection strong and this will boost the confidence and you can follow this method also.

Thanks and Take care.

You are welcome to ask follow up doubts.

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