Hi,
i suffered with my own set of anxiety symptoms for over two years before starting to see any light at the end of the tunnel. And that light was provided by anti-depressant medication. The way you describe your situation reminds me a lot of mine. Okay, your symptoms are completely different to mine but they are very specific. And mine too were very specific, and didn't change much over time. And they were very very real, and I couldn't believe that they were purely down to anxiety. I had test after test, all with no results. And I went back and forward to my doctor during the two years and half the time simply ignored their advice and their anxiety diagnosis because I just didn't believe what they were telling me.
The fact is that, by your own admission, you have had any number of tests that have all come back negative. Maybe there is a 0.01% chance that they have missed something, but it looks 99.99% positive that they have done their jobs properly and their is nothing seriously wrong with you. The same as there was nothing seriously wrong with me. But that doesn't mean that you haven't felt legitimately like crap for the last year, because I know as well as anybody that the symptoms feel 100% real and they can be hell to deal with.
I'm 29 now, my problems started in 2004. I went round in circles for ages until I finally accepted that just maybe this was all anxiety and maybe the anti-depressants really could help. Anti-depressants aren't only for the depressed you know, i've never felt depressed during my illness. They take a little time to kick in and there can be some initial side effects although nothing to lose sleep over. But they really can make such a difference and have been a godsend to a lot of people. I am only three months into my medication so I can't comment on long-term use, but so far I am feeling as close to being well again as i've been throughout the full two years. My appetite is great, i'm sleeping great, i'm feeling energetic and enthusiastic and driven. Such a huge contrast to the weeks and months I spent not being well enough to even stand up!
I am sceptical about the medication your doctor has prescribed, in particular about how it can possible help with the anxiety. I am not a doctor so this is just my opinion, but I have not read anything that suggests propranolol should be used to treat anxiety. It fits with your other symptoms, but not with anxiety. So maybe you need to go back to your doctor and talk about the possibility of trying an anti-depressant medication. There are many to choose from so if one doesn't work for you first time then there are always alternatives. Personally I am taking cipralex (medical name escitalopram) which has worked wonders for me (and a lot of other people).
Like I said, these are all just my opinions and I am not medically qualified. I'm just another person who suffered for far too long like you have. I don't want to sound like i'm pushing medication at you, it has to be your choice.
I wish you all the best...