Heart beating fast and hard after just one or two light drinks

Hey! Yes, I am guilty of not going to the doctor with this but I’d like to get an idea of what I can expect. I used to be able to drink, go out partying and so on. That, of course, included a considerable amount of alcohol. However for the past 8 months, I suddenly seem to not be able to withstand alcohol at all! It started with me getting hungover very easily (from just 2-3 beers) and it has gotten worse ever since. I’m now at a point where a single pint of beer will make my heart race, beat hard, feel nauseous and dizzy. Interestingly enough, I do not feel drunk! Also, the symptoms as I just described ONLY happen at night! When I’m lying down, eyes closed and ready to sleep. I feel my stomach get bloated and after 30 minutes my heart suddenly starts racing and I get extremely nauseous. Only thing that seems to work is getting up, turning on the lights and drinking water until morning arrives. Has anybody experienced something such as this?