My husband was put on a beta blocker after his stents were put in. Even though he told them his resting HR was already in the 40s and he was on another drug for high bp, they still tried it. After 2 weeks he went back to the doctor and insisted he get off the drug. Another friend of ours could not function on a beta blocker. He had no energy and could barely work.
There are lots of alternatives for anxiety. It would be safer to try short term use (2-3 months) of something like Ativan, which you can wean off of fairly easily (I did it in 6 weeks). Also, acupuncture totally cured me of my anxiety surrounding my medical issues. You need to see a psychiatrist or psycho-pharmacologist to really get the right thing. Family doctors just aren't as informed about this stuff.