Frustration

Our son BB has always been an overachiever of sorts. He has always been the one we knew we didn't have to worry about. He usually does what he's told, he's pretty responsible, and he's very reliable. BB has been a straight A student since he started school. He loves to read and draw. He has the funniest personality of any kid I've ever met. He's always been solid as a rock. Lately our little guy has started to stumble HARD. He is not doing his school work, he's talking and being disruptive in class, he's been caught in several lies, and I even caught him reading a book he know's he's not allowed to read.
Now don't get me wrong. I realize he's just a kid. I know he's human and he's gonna make mistakes. I know he cannot be perfect all the time. What I'm struggling with is that it's becoming an everyday occurrence. I don't trust him at all right now. I'm so angry at him, and so hurt by him. I have gotten emails from two of his teachers and it's only the beginning of the 2nd quarter. I have NEVER gotten a negative email about him. I am just at a loss of what to do. He is not turning in assignments, he's "losing" things, and he is just plain all out lying about his school work.
I feel terrible about being so angry at him, but I am so hurt by this. I just don't understand what is going on! As I type this he is sitting at the counter at 9:00 doing work that was due last week. He has been working on make up work all week and still doesn't seem to understand the gravity of his situation. We have taken away all of his privileges. He sat down on the couch to read a book tonight and I had to make him put it down to do more homework. This is breaking my heart. I just don't understand and I just don't know what to do!
I have been trying so hard not to constantly ride him about it. I have tried to be encouraging and patient. I have tried to keep in mind that middle school can be a big adjustment. Tonight though I finally lost my patience. I got an email from his science teacher asking if he could start staying after school to catch up because she is concerned he won't be able to if he falls any further behind. It would be one thing if the work was too hard, that I could understand. He's just being lazy. He even said as much to me. Bless his heart, he has admitted to all of his wrong doings when asked, but he has been very sneaky until he got caught. I'm just at a loss. I am just sad and frustrated.

Amy