Help! I can’t cook any more!

Help! I seem to have lost the knack of cooking tasty hot meals somehow....I am 67years old, widowed many years with a “gentleman friend” of 82 yrs who is diabetic. I cook for us every day but recently I seem to be struggling to put a good meal on the table.... drab plates of dull food. We try to eat healthier now, many foods are out (red meat, pies, fatty foods) so we eat a lot of vegetables and fish but the meals I cook are boring. Have I been cooking too long? (Since I was 18 at college) or is it the constraints I am putting on the food we should eat now? Any help would be welcome...