Blacking out every time i drink normal?

Im still learning to use this app so please bear with me. Sonive been a heavy drinker for about 5 years or so. I can go through a whole handle a night, easy. But lately even just the smallest amount i black out now like my body is rejecting the alcohol or something. I dont go out to drink and i dont drink caffeine with my drinks. So theres no way my alcohol is spiked. I buy the bottle. Go home and drink alone. I think something is physically wrong or im dying or something? Advice, thoughts, anyone has have this issue? Obvious im trying to quit drinking but why is this happening? What is going on?