Hi there.
I think you should trust your doctors advice.
They are experts in their field and deal with these things all day long.
Im not saying that there is nothing going on, but it appears from the outside looking on, that possibly you are just absorbed by the problems you have had and that its a probable anxiety issue thats fuelling things a little.
All your tests have been ok as far as your doctors are concerned.
You need to try and tune out of the medical problems which seem to have become a monster in the room.
Go to your GP and seek his advice, go open minded and try get by one day at a time, eventually breaking the cycle of worries and fear you have.
Incomplete right bundle branch blockage is rarely significant. I've had one all my life, never even comes up anymore. Also, pain related to the heart are rarely sharp or short in nature so I think you're more likely dealing with anxiety issues.