Hello ,

I am a 19 years old boy  and when I wake up in the morning i fell really weak like I am lifting a ton.Cant concrete after a period of time feel really weak.Went to doctor and told him got a blood test done he and I saw oxygen saturation in blood was less , he told me not to worry .Lately i am having pain in my chest and back of my head  sometimes i go blank , when I try to play my heart beats rapidly i can feel blood pumping in my eyes head and later I become weak. I am a vegetarian I keep on eating i havent put weight for my eating habits.May I know what is wrong with me , how can i change it .I really need help.