Can I be oblivious to my possible lactose intolerance?

Patient: Am I lactose intolerant?

Symptoms: I’ve been drinking milk and eating cheese like crazy my whole life. I’ve always felt lethargic, bloated and gassy after having dairy though. Sometimes I’ll have diarrhea, painful and burning sensation in stomach, sensitivity to light and smell, and i’ll feel like I have to throw up which happened today after I ate pizza; and usually happens a lot after eating pizza especially. Ironically, pizza has been my favorite food for a long time.
Sometimes the pain in my stomach will last for a very long time and I’ll be crying and on the floor like it’s menstrual cramps or something. That has only happened 1-2 times though.
When I was in school everyday I would be light headed, gassy, and have a “gurgling” stomach which would be so embarrassing.
I don’t know if i’m lactose intolerant though since I’ve been eating dairy for a long time and this wouldn’t happen every time I ate I would just get bloated,gassy and lethargic but not have to run to the bathroom.
So can I be lactose intolerant but be oblivious to it; which is why I never knew?. I don’t think my parents would believe me since I’ve always been a notorious dairy eater.
Update 1: I am half korean btw and I know a lot of asians are lactose intolerant.