It sounds like you are suffering from Sleep Apnea. Waking up in the middle of the night gasping for air is from not breathing. Go for a sleep study to confirm this and if it turns out to be true you will just have to sleep with a machine.
There is actually numerous possible diagnosis for this. Nocturnal anxiety, sleep apnea, and asthma are just a few of the possible conditions you're going through. Consult a doctor and get the proper tests to be certain.
Try practicing breathing exercises before sleeping, also drink enough amount of water before going to bed.
Thank you I think we are often the best judge of when our body is not right. I thought asthma at first as there is a definite rasp/wheeze during sleep. Patient has physical demanding job (warehouse operative) which I have known to worsen asthma in other cases. Think I am going to keep records so I have some idea of how often these episodes are occurring when Gp asks! Thanks