(TW for violence) First severe meltdown in a long time + bad substance experience

So this is all from my girlfriend's experience because I don't remember clearly what happened because I tend to blackout when I have a meltdown and on top of me being very stoned it probably was really bad.

It was last night and the day before my girlfriend's birthday she had some weed with my mom (weed is legal here in Illinois so it's fine + we're of age) and my girlfriend offered me some weed and I accepted I don't do weed much and she said I took too much and was "greening out".

My mom had the munchies for ice cream so she told me to get some Dairy Queen for her, my girlfriend and me and me being very high I accidentally requested it for pickup instead of delivery and we don't have a car. There wasn't anything I could do to get the money back via app so I had to call Dairy Queen myself to get the money back and they said it would take 3 to 4 days to get in my mom's debit card.

(I already told you about me and my mom's relationship in and the financial situation in a different forum so of course it's gonna be bad)

My mom started to yell at me if Dairy Queen doesn't give her the money back she would "chew my butt out" and that's when my girlfriend told me I broke down. I started to cry and apologize over and my mom started to yell at me more because I was "making her feel bad" & "was embarrassing her in front of my love".

My girlfriend took me to my room to calm me down but she told me I was punching myself in my head really hard, I was biting myself and I tried to grab at her and the only thing that got me to calm me down was her getting my dog from the other room to me so my dog can calm me and after that I was fine I watched some videos on my phone and fell asleep.

My girlfriend is also worried that I've might've gave myself a concussion because how hard I was hitting my head I have a headache and a bruise to where I was punching and she said it's not a good sign.