Hello Friend, Good that you are seeking a help here. Laziness, lack of interest, lack of concentration etc are symptoms of depression. As mind and body are interlinked it may also influence your physical health conditions as well.
Just observe and analyze what is happening in around your life on your home environment, lifestyle, relationships or family issue etc. Any of these could influence your mind with some negative thoughts or worry or fear which inturn trigger depression.
Be positive. Depression is just like any other physical illness and can be addressed through counseling session and few lifestyle changes and self therapies or excersise to overcome.
Next Steps
Call me directly or online through Practo app for further detailed evaluation to identify and isolate the root cause and recommendation suitable solutions. Be positive. You will be alright soon.