Why cant i lose weight i dont eat alot i tried exercising i felt better but still am heavy and flabby ?

welcoming the new year again heavy i feel so un y im going on 50 i need to see quick weight loss i feel discouraged i lose a few lbs and i retain water im in my perio menopause i have my menstrual periods for 3 months and feel better and then they stop and the hot flashes start and i get very tired can any one offer an advice