When i do not get enough sleep, when i wake up, it is hard for me to breathe throughout the entire day. why does this happen?

Sleep Apnea?: Do you feel tired too? Check for sleep apnea with a sleep specialist. I would take this to the next step ..

Many Reasons: One possibility is sleep apnea combined with acid reflux. You should get a consult with your internist to discuss your options (ex.Sleep study done or and/or endoscopic exam(or other diagnostic exam for acid reflux), or other diagnostic procedures) to get an accurate diagnosis first.