Hello and welcome to the Forum. You may want to seek out the opinion of a second cardiologist with your family history for some further testing if it is called for. Also you may want to make an appointment with a Gastroenterologist you could investigate your GI system.
If there does not seem to be any physical reason for your symptoms talk with your PCP about therapy to help with anxiety. You lost your brother less than a year ago and I am so sorry. This could be the cause for some of your anxiety - losing someone so close to you is going to bring you all kinds of feelings so let the feelings in and know it is OK to grieve.
We also have a great A & P Forum if you want to drop in and post a bit about your problems and see if we can help you.
Moderator: Anxiety, Osteoarthritis,
GERD/Heartburn and Heart/Cardiovascular Disease.
"Learn to get in touch with the silence within yourself, and know that everything in this life has purpose. There are no mistakes, no coincidences. All events are blessings given to us to learn from."~ Elisabeth Kübler-Ross