This probably isn't the answer due to the age situation. However.. it might help someone.. My wife, who has always been rock-stable and never known anxiety suddenly went down with scary symptoms - bad chest pain which extended up her neck, trouble breathing, ashen skin... and extreme terror. Paramedics were called and rushed her to A&E. ECG and blood tests revealed no heart problem and it was put down to a panic attack, which she had never had in her life. The attacks occurred several times more, accompanied by severe depression, but we were able to deal with them knowing that they were not life-threatening, but still scary. After various blood tests over a period of several months it was eventually established that she had a hormone deficiency.
A change to her HRT dose totally cured the problem. Please get help - it might be something which can be sorted quite easily.