I feel you OP. My brother has had drug problems for years did steal things from me. My cousin claims he stole things from her as well. Ask your parents for an actual lock on your door, not one of those shitty ones that can be picked with a coin. Make sure your things are locked up anytime you leave the house. They won't ever get better until they want to.

Kick his ass

If someone touched my Clarinet, I would smash their face.

I am sorry, but I don't understand how you, if you propose, don't know the answer actually beforehand... You guys don't talk or what? You have to know you SO's opinion on this thing already (doesn't have to be that you asked before, just that you guys talked about important things, like life, plans for future, maybe children and whatnot), because if you didn't, then there is probably some problem in communication in your relationship that you should work on, or your relationship is just not ready for this kind of things yet.

If your in Houston you can have mine, I don't use it anyways

Honestly he really does. That's your family, probably the only people who still talk to you besides your druggy friends, and you steal from them? Today we had someone came into school and talk about his spiral down to drug and alcohol abuse and he said he would steal things even if he didn't want to. He said he would cry while stealing things but he had to. He's better now, and it sounds like OP should get her brother some help. He doesn't want to go that far down the hill.

is it drug for you or her?

I have a concert on Monday and wensday, I play trumpet, but that's f***Ed up, sooooooooo sorry.

That's not legal. He can't sell something that doesn't belong to him. Go to the pawn shop and get your property back -- they can't possibly refuse to give it to you, every pawn shop in the country knows the meaning of the phrase "receiving stolen property".

Yo that's crazy I have a concert today and I play the clarinet