can someone please kindly explain things to me i read the whole thing but i felt like i un...

Okay, so after rereading this slowly, I think I get it. Bad English and essay incoming!

Basically, Andy was always a little psycho killing animals since he seems to be drawn to things that seem helpless and in need of care. Bran was in a boy gang where they do boy things and it happens that on the day they bullied Andy and almost killed him, Bran saved Andy, but as Andy watched he was attracted to the face Bran made where he almost died (start of his yandereness).

As they grew up, it was apparent Andy was obsessed with Bran due to that helpless face he makes when he has seizures. That's why he was around all the time to take care of him. This is proven during that scene when kid Bran is getting loaded into the ambulance and the EMTs asking Andy where Bran's parents were and he has a mesmerized look. And this is further proven that Andy is attracted to Bran's seizure face when Bran gets a seizure and Andy has an erection and rapes Bran during that captivity scene. More proof is when Andy was driving and thinking about their past and the expression of Bran's bloody face. Bran was trying to turn his life around when they turned 18 though, to better his life, but it seems that Andy was the one who ruined his chance at living normally since he most likely drugged/affected Bran when he was taking care of him. Andy wanted to keep Bran helpless so he can care for him forever. He was also spreading rumors and affecting Bran's image so he can seem like a druggie which affected Bran's chances in life. He also turns Bran into an alcoholic to further incapacitate him.

The people Andy killed were mostly people who can affect his life with Bran. Like the medicine dealer at the hospital, he was trying to sell that he can better Bran's health and that was going to threaten Andy's life with Bran. If Bran gets better, Andy loses his object of obsession. He only kills to maintain his ideal world with Bran, not because he mindlessly kills.

I definitely think Andy was drugging Bran's food. Bran had memory troubles legitimately because Andy was drugging him.

Does Andy want to kill Bran? Maybe, but eventually no. In the scenes where Andy fantasizes killing Bran, it's out of anger since Bran was being an asshole, but Andy only stops this because he remembers why he's with Bran in the first place. Not because he owes him for saving him, but so he can continue seeing the pitiful look of Bran.

Does Andy love Bran? It seems that they did have a relationship at one point, but Bran probably did not want it romantically since he was not gay, so they kept it as a sexual relationship. Andy was more in love with Bran's helpless look rather than Bran himself, but I think it did evolve to an actual sick love for Bran. Towards the end where Bran tries to escape, Andy doesn't want Bran to die and looks actually concerned for Bran when he asks him if he's hurt.

As Andy watches Bran have another seizure near that train track, he realizes he truly wants to take care of Bran forever because he is like a helpless little lamb.

Oh, and Andy also killed those who are harmful to Bran. And yes, they did eat the people he killed. "Familiar smell of beef" was the scent of cooked human.