It's not a small thing nor are you being vain. Age should not be a factor in hair growing back, I was 68 when mine grew back (and much less grey!). Five months seems long enough to take some action. Are you able to see a dermatologist? Hair growing back is something we all cling to, and look forward to. Yours may just be very slow but there may be some other factors, which might be remedied. If regrowth is going to be very slow, or patchy, is a wig a temporary option? It can be a great morale boost - just walking down the street feeling and looking normal. Many wigs are light and easy to look after. Best wishes.