I recommend that you make an appointment to see your primary care doctor
. Generally when people have true wheezing it is because they have constriction of the small spaces of their lungs, causing turbulent air flow and the wheezing noise that asthmatics get when they're having an asthma
attack. People can sometimes make noisy or high-pitched breathing sounds from other parts of their airway, and even sometimes from anxiety
or a feeling of breathlessness. Definitely any pressure against your throat can make it hard to breath and can also make your breathing sound more high-pitched. You could also have something within your chest that is obstructing the flow of air that only becomes noticeable with increased pressure, though it may also be that the feeling of pressure makes you feel like you need to work harder to get air. Without seeing the spot and listening to your lungs it is a little hard to explain the symptoms that you have observed, though it is reassuring that the rest of the time you feel well. Since this problem is bothering you and interfering with your sleep I do think it would be a good idea to make an appointment to see your primary care doctor. Your physician can take a good listen to your lungs and will have a better idea of what exactly you are feeling and what further steps should be undertaken.