AITA: Sibling Loaner Loaned

AITA?

Here’s a backstory, my brother moved down the street from me (our hometown is miles (800) away). He’s in the young 20’s, has an apartment (with my help), no job, is dating a 17 year old (small town, mom doesn’t care what the daughter does, no dad in the picture). My brother and I lost our parents young (by the time he was 10). He has lost two jobs since December, never told me (I found out anyways) and spends his money on the everything else but bills (and no bills are not paid). I told him I’m cutting him off from my family, I have two girls (2.5 and under) and I don’t need them to see me upset with my brother or being around someone who lies about the simplest thing. You could ask him if the sky is red and he’d say yes even if it’s clearly blue. He denies dating this 17 until I told him to show me the hickies he left on her (which she was flaunting). He has a few of my things that we let him borrow until he got on his feet (which he did great the first three months he moved out here). He’s since loaned items to his friends that were loaned to him. He doesn’t see the problem with the loaning loaned items or the fact he’s dating a 17 year old. I just need someone to tell me I’m not an ahole for cutting him off from my family/being upset with him.

ETA: My brother is 21, will be 22. The girlfriend just turned 17 in Jan. I told him if he didn’t let me get my stuff tomorrow, I’d have a police escort help me get it. To which he responded with he loaned a tv to his friend that will be back on Friday.

ETA2: I’m (28f), brother is (21m)

ETA3: I received my gaming system last night. He tried to push it off to today (Wednesday) because he didn’t feel good, even though he had “work stuff” and had to spend time with his girlfriend. We both agreed to Tuesday night. His girlfriend tried to get snippy and loud with me, and he kept saying I’m not family and that he’ll get me it tomorrow. I did stay until I got it and of course the tv he loaned was stolen from the friend. We will be giving my MIL a tv to replace the one that was stolen. I did suggest he take his last paycheck this week and open a new account I’m not on so I can’t see what or when he spends his money or overdrafts. I’ll only hope he straightens up but I’m not going to risk my happiness and family’s happiness worrying over the choices he makes.