motivation and energy

Hi my name is Mandy and have noticed over the last several weeks that I am lacking in motivation most days. I only work 3 days a week and I am home with the kids all other days. My husband goes to work at 8pm and doesn't return until morning anywhere from 8 to 9 am. Then he goes to bed around 11 or 12 sleeps til 6 or 7. I am not sure if I am posting in the right topic but I am not sure if it is depression most days or weather or just tired. I have a hard time making myself get up and motivated after the oldest one leaves for school. I have three girls. My patience becomes very short and can become irritated very easily. Is this normal for a somewhat stay at home mom. Am I depressed? I feel like my balance in mood is all over the board. One day I feel fine and the next is completely opposite. I try and do cardio every night and weights every other. Trying to workout at least 4 days sometimes 5. Maybe I should go back to see my dr. I don't want to take any anti depressants though. Any help would be greatly appreciated. Thanks