I had a problem of having a short breath long time ago. now it's becoming too much. i cannot sleep at night because it's much but during the day i breath ok.

Evaluation: Please see a Pulmonologist for an evaluation. Cardiac and pulmonary testing may include PFTs, an EKG 12 lead, a six minute walk test and imaging. Night time shortness of breath may be associated with asthma and allergies. Wash sheets and pillow in hot water. Avoid common allergens such as dust, mold and animal dander. If you are a smoker, COPD or COPD asthma should be considered.

Anxiety: Since you're not experiencing shortness of breath with exertion but only while lying in bed, I feel that anxiety is playing a role and that you're focusing on your respirations which should be an automatic process regulated by the brain stem. Serious issues manifest breathing difficulties when physically active and not only when at rest. Think about something else when trying to sleep.

Breathing problems: Have you been noted to stop sleeping while asleep? Do you snore very much? Over weight? Do you ever wake up gasping for air? I do encourage you to get medical evaluation. It could start with your primary care provider (who might need to refer to a sleep medicine specialist or a pulmonologist).Take care