What actually is trauma?

How do you know if you've experienced a true "trauma"? I always feel like what I've experienced shouldn't count, and yet I have a PTSD diagnosis.

I had what some would consider a great childhood. Father that provided well and from what I'm told a loving mother. But all I remember is the drinking that got worse when I got into high school. I literally have little to no memory of her before then.

She knew it was genetic and still started buying me a bottle of wine a day the summer after my freshman year of college. I wound up hospitalized for almost dieing of alcohol poisoning over 10 times by the time I was 21. Already through rehab by 23 and told not to come home if I didn't support her drinking.

I am the one who identified her jaundice at age 25, took her to the hospital myself where she ultimately passed away in the most horrific way. I went through the ED codes with her, as the healthcare person in the family.

Does this count as "trauma"? I'm not even sure anymore. I just know its been almost 10 year since she died and I'm still angry, wondering what she would think of my daughter who is just as wild spirited as me.