Cold means having running nose, cough and fever. Since u don’t have those symptoms cold doesn’t look like a possibility. Flu , yes u may have abdominal pain and general aches in flu. Measure ur temperature and watch for any other symptoms. If it’s flu, don’t worry! U will be better in 3-4 days. As u r saying ur food habits r not that good , u may start healthy food from now! Drink lots of water and fruits.