Blindsided

So things had been going relatively well. Jr.'s car was up and running. He isn't around much, but he hasn't been causing any major problems. Comes home smelling of weed every now and then, but there's not much we can do about that. He finally found a job and it's a good one. Great local fast food place that has an awesome reputation for treating its young staff well and keeping them happy. I've always said he had the right personality to work there and I'm hoping he does well.
We even decided to get another dog. Didn't really want to, but Braddock has been super mopey and clingy and so happy when Jr's girlfriend brings her lab over to visit. We found a pitbull rescue and we are really hoping it'll make him happier. She's super sweet and when they met she seemed to already recognize him as the alpha dog. I have to admit that part of me went along with it because of the idea of having something new to love that doesn't make me feel like crap. (not the right reason to get a dog, but it was the "pro" that tipped the scales)
Flash forward to today, to this morning, to about 20 mins ago. I get a call from Jr.'s school. They already said that if he gets caught skipping class again they will expel him. He would have to finish out the year at an alternative school in order to return next year to graduate. Well he's not skipping class; he's just decided not to go at all. He hasn't been there since last Thursday. He gets up every morning. He puts on his uniform. He leaves the house. I had no reason to suspect anything. I finally get him on the phone and find out that he's been chilling at a friend's house playing x-box and sleeping (probably more than a little weed smoking thrown in because this particular friend is notorious in that department).
I don't know what else to do. My husband insists that he graduates because he might wind up deciding to go in the military once he realizes how hard it is to get a job without a secondary degree. I want him to get his GED and move out like he's threatened to do so many times. I don't want to screw up his opportunity at this new job by taking away his car. I can ground him, but with his own transportation I can't make sure he comes home straight from school or work. It's like he knows he's got us over a barrel.
You know what it is, it's like when you know you are going to suck at something and you just want to do it and get it over with. Because you know how awful you are going to feel when you are in the process of sucking and you will feel compelled to try things to reduce the amount of suckage, but to no avail.  You just want to get to the other side where you can reflect on how bad you sucked. That's me right now. I just want him gone so I can reflect on my failures as a mother instead of flailing around and trying desperately to salvage some decent parenting. It's a lost cause.
You can point at my daughter and say I'm not a complete failure, but I'd have to remind you that both of my parents sucked and I managed to make a decent human being out of myself. So I don't know how much of her I can take responsibility for.