There is no doubt that you have depression
...as you are on beta blocker
for so long it is probable you have developed depression due to it as they are prone to cause it but not necessarily this is the case
Secondly propanolol is the drug of choose for tremor
so if you had problem of tremor , the doctor had no choice and you should have visits doctor regularly so that he could have tapered your medicine in such a long time...now your tremor are due to it's withdrawal.....but still there is hope...you consult a psychiatrist
who will reduce your propanalol and give you another medicine to tackle your problem and that can also help you in your depression also...