Stress/ Feeling down and unhealthy :(

Hi all im back at university now so im once again poor! for the past two weeks ive been feeling very low and sluggish and just unhealthy you know? like i need a boost and to kick start my weight loss again. I have been struggeling to get to the gym because of the feeling sick and awful from stress. was just wondering if anyone has any advice on food and stuff to help me out for a bit? x