Talk to General Physician on Low On Energy, Trouble In Concentrating, Tired All Time.

AOA, Hope you are well, I feel tired all day, I have almost 0 motivation to do anything. I am super unproductive these days, I am enrolled in hardest semester in my degree program. Things are getting wrong cause I am super lazy and tired as hell all the time. I am really bad at focusing. When I convince myself to do some work out, I hardly do workout for 3 minutes as hurriedly I always become tired. I feel comfortable lying on bad all time. Can you give me tips how I can be productive and high on energy. Is this happening due to some underlying deficiencies ?? I also feel headache on back side and trouble taking in breath due to nose blockage sometimes.