SOMEONE PLEASE GIVE ME ANSWERS (also spoilers)

Okay so I watched this movie on Netflix about 3 hours ago and I must say it wasn't really that bad at all. Throughout the whole movie I was having mini anxiety attacks like for real that *beep* was gnarly af. I just don't understand what the ending was like was he so angry at the time he really just shot them right then and there and imagined the whole on going process after that because if that was real and he real imagined that... THATS SO TWISTED BRO?! If a someone can really fantasize or hallucinate, whatever you would prefer to call it then that's seriously some trippy stuff. I also want to know where this "true story" is. Trust me people I have looked up and down and all over to try to figure it out or find out the slightest bit of information but I can't find anything! & that seriously pisses me off because I'm the kind of person that doesn't stop thinking about something until I figure it out!!! Ugh now I'm out in this terrible position and I truthfully think the actors fit the characters. His accent wasnt that bad to me but I did read other reviews stating that this filmed was based in Louisiana so I don't know he difference but a Louisiana accent and Arkansas accent is but I didn't think it was bad at all. For someone that lives in the city of fortsmith for 4 months (I had to move back to California. Just wasn't my thang) I thought it was pretty damn real. It really hurts my heart she would do that to him on their anniversary too. Like that's so *beep* if this actually based on a real story bc that's so twisted and freaky. this just can't be based on a real story the whole fantasy dream he had just can t be real that's so detailed and so real??? I thought it was so real the ending just screwed up the whole thing! That's the only part that went wrong. Sammie puts one bullet in the gun and spins it as in roulette and I think *beep* that bitch "peaches" she cheated on him on his anniversary & he clearly was so in love with her but she's a hooker for sure for sure!!! Who even does that?! "Oh baby I did it because I wanted to get you a nice anniversary gift but I'm paying him back" that's so sickening to even think about someone doing that to me. Like it actually got me kind of emotional too. It was just so intense but yeah to hell with peaches I don't want to necessarily say she should have died but I definitely do think Sammie should have left her but then again he was so happily married to her and you could tell from the beginning to end he would've never suspected betrayal at all. I think one of the best parts is when he *beep* the black guys wife and peaches and her lover start freaking out like it didn't hurt Sammie literally watch his wife get pounded out?! I hope this isn't real and I really hope no one had to see that or had to be killed because this is honestly sick and twisted. Super rad for a movie but not a true story hell no.