I hope you have the type of relationship where you can express these feelings with your doc-- that might open up a dialog that leads to some reassuring comments from your doctor. The pain is probably something from inflammation, like chostochondritis-- a condition that is painful but otherwise relatively minor. Much of medicine is 'playing the odds', and it is very unlikely that you have something more serious going on; if you had, for example, lymphoma causing a mass in your chest that puts pressure on things, you would be dead by now without treatment. A heart condition like an aneurysm would be progressive as well (and also rare). If you have 'marfan's syndrome' (if you are over 6 feet tall and very thin, and have a history of family members who died young) then a thoracic aneurysm would be more likely.
It is very hard to prove a 'negative'. Another gentleman on this forum has similar symptoms and similar concerns. He has had every test in the book (almost, anyway).
I suggest you try a gentle, non-insulting talk with your doc about your concerns; if he/she is truly 'amazing', perhaps you will have a more reassuring discussion about his thoughts about what is and isn't going on.
I can sympathize with you. I have had almost every test in the book to try and nail down a physical cause for my mid chest and back pain and a tight chest sensation.
If you read some of my posts you will see some similarities. Dr. Junig has been very helpful for the past 8 weeks. I have depression, anxiety, stress, Hypochondriosis and somatization disorder. I have been very worried and associate my pain with cancer or heart disease. I have an echocardiogram test result pending. If it is normal it is my last test.
I must try to let go of my fears and constant need for tests/ constant family Dr visits and move to dealing with a Psychiatric doctor and anti anxiety and anti depression medication, relaxation techniques etc. My Dr. believes through exclusion of diseases from all the tests I have had to date that I suffer from fibromyalgia ans somatizeation disorder, which can cause pains all over the body and my worries stress anxiety and depression and fixating on the pain make the pains that much worse, it is a vicious cycle for me.
In any event please make sure you have a Dr that takes you seriously and runs the appropriate tests if he feels the need to do so. You can always seek a second opinion. If the tests are negative/normal then perhaps a combination of therapy and certain depression meds will help your symptoms, only your doctor(s) will know what is best for you.