Hello...from whatver you are going through looks like you are suffering from depression..sadness,loss of interest,decreased self confidence, loss of interest to have food,difficulty in concentrating, sleep disturbances are all symptoms of depression. So you can also think is there any reason for me to feel so..like any stressors which has trigger these symptoms. You will need detailed evaluation with a psychiatrist.
Next Steps
having said that you can also push yourself initially for doing physical exercise and then continue daily.
maintaining a daily routine.
sharing what you are going through with your family and loved ones. They can be of great support.
Health Tips
consult a psychiatrist at the earliest.