Why do I wake up scared and gasping for air after having beers and having a hangover?

Alcohol withdrawal. part of the hangover is short term alcohol withdrawal. Anytime somebody has more than about 4 drinks, they will go through a short period of alcohol withdrawal, which shows up as anxiety, shaking, shortness of breath, high blood pressure and a fast heart rate. The only good way to deal with this is a medication called beta blockers, such as propanolol. You will need to see your doctor for that.
Sleep test. All of your symptoms may indicated sleep problems that can be life shortening or life threatening. The only way to know if there are serious problems is with an overnight sleep test. I encourage you to seek help.