If you are taking whole-day propranolol, you are likely to be tired. The function of propranolol is the so-called beta1 and beta2 blockade. The dominant majority of beta1 and beta2 cell receptors are on cells of the heart(b1) and lungs(b2). When propranolol reaches them (in blood circulation), it decreases the function of hearth (lower heart beat), and decreases the function of lungs as well (lower frequency breathing). Therefore, it is likely that you feel tired for your heartbeat was lowered and your breathing was lowered (for a reason; ask your doctor). You may gain weight, basically for the reason that you feel quickly tired when exercising or doing anything. I gained 30kg over 3 years, but I was truly lazy and was eating crap food. It is all about finding the right medicine for you. You should probably try a few or see a specialist if the medicine does not suit you. There are tons of medicines now available, but you might be struggling getting them on the NHS.