You are having 'obstructive sleep apnoea', you need to get yourself checked from a good ENT specialist
. If at all there is obstruction it can be medically or surgically corrected. If the obstruction is not from the nose then you need to get a thorough check-up done to look for the site of obstruction and managed accordingly. As of now, try lying on one side rather in upright position. Take steam inhalation before you go to sleep.
Dr. Naveen Kumar