I can understand your concern . Beta blockers are prescribed as first line antihypertensive especially in young hypertensives considering the fact that they have over active sympathetic system..although the first choice is always ACE inhibitors such as losartan and diuretics . Apart form decreasing blood pressure beta blocker has major effect on heart rate.they decrease heart rate. It has no addiction potential but when it's effect will disappear heart rate will increase . Now you have to assess on losartan and hydrochlorthiazid your blood pressure is well controlled or not.if controlled it's good if not we can add beta blocker in low dose..One thing that I would like to emphasise is this that if you are correctly diagnosed with hypertension you must take antihypertensive to keep your blood pressure within normal range . Your height is 5.10 and your weight is 120 kg this is too much you should maintain your BMI in the range of 19.5 to 25.their are some non pharmacological measures that can help you in managing your blood pressure . Such as low salt diet weight reduction with BMI less than 25 moderate alcohol consumption and physical activity . You have to seriously consider all these also.this may happen that you may not any medicine as Your blood pressure is not too high.hope this will help.