Beginning to worry about intolerance or allergy

I am 25f and used to drink beer 3x weekly. I usually would start to feel sick, not nauseous but more like a flu once I drank too much. I was average BMI and now I am low average/underweight BMI and I get the flu feeling after just one beer now.

Headache, severe sinus inflammation and stuffy nose, itchy throat, etc. I just feel awful. I usually have to take nyquil or benadryl to be able to sleep if I reach this point. I feel like I’ve hit the peak of a bad flu.

Just curious if this is normal or not