I can’t hold my liquor.

I don’t know what it is, but my body just doesn’t like hard liquor. I can drink a few beers and be fine, but a shot of vodka makes me sick to my stomach before it even gets there. It’s not that I necessarily don’t like the taste, but just the fumes of the ethanol seem to be rejected by my body as soon as the alcohol hits my tongues and gives me an urge to vomit. I don’t drink often so this may be a factor. I don’t think I have an allergy though, because I never have any allergic reactions when consuming something with a lower ABV and catching a buzz. I can manage to painfully down 1 or 2 shots but anything more than that is pretty awful. Is this just a genetic thing? Weak stomach? How do I enjoy liquor?