I was coming down on meth arguing with my dad, he was wrong, so I shot him

Two years ago, I had been smoking a lot of meth and had a serious problem. I was on a 3 day long binge and i was completely fricking out of it during the comedown. Me and my dad got into an argument regarding Back to The Future, he insisted they needed 1.22 gigawatts for the delorean, but i kept telling him it was 1.21, during the previous month, before i smoked meth for the first time, i had got my concealed carry license and it was always on me. it was a Ruger LCR. i kept screaming at him and repeating “google it, google it, just fricking google it.” I had struggled with domestic abuse and physical violence from him my whole life but it had been awhile since he last hit me, suddenly, he got up off the couch and stood up as i was screaming at him to google it, raised his hand at me, and i pulled out the ruger and shot him in his kneecap in a fit of rage. I realized what i did immediately after and called 911, when the cops got there, they took him by ambulance and everything turned out to be ok for him. i was locked up for several months and only just recently got out a few weeks ago. I think this event was the wake up call i needed and i feel an overwhelming guilt for this, especially thinking about how stupid it all was in retrospect, especially the topic of the argument, my family hasn’t spoken to me since this event and i honestly don’t blame them. I don’t know if i would either. But i hope things can be patched up someday between us.

Edit: Wow i’m surprised at the attention this got, i’ve been trying to answer all the questions in the comments but i’ve been quite busy, thank you for all the support and nice words regarding the things i shared here.