Like Mother Like Son?

I've done a lot of soul-searching in recent months.  What do I really want in life?  What do I want for my family? Where do I belong?  What does God intend for me?  And many, MANY more questions.  I've come to a few realizations.  Not very many answers for some of the questions but realizations about the way things are.  Here are a few-
My children are slobs because that's the example they've been given.  Now, don't get me wrong, they are way worse than I could dream of being.  When I drop something on the floor, 99% of the time it gets picked up.  I don't leave food in my bedroom (rarely take it in there), I don't take food to the family room (it's not supposed to be there anyway), I don't toss all of my stuff on the floor the second I get in the door, etc., etc., etc.  On the other hand, I've never been much of a housekeeper.  I stack things.  If there are papers I need to do something with, they go in a pile.  If I'm busy with something and the children bring papers home from school, they'll probably end up stacked on the coffee table.  When the stacks get high enough on the kitchen counter, I'll either sort through them or just toss it all in a box until I feel like sorting them (boxing them usually only happens when we have company coming and I'm totally embarrassed about the house).
And then there's the subject of being lazy.  I have a good work ethic.  When I have to.  If I don't have to, well, I get lazy.  Don't ask me how many books I've read since January because I lost count at 15.
I've been a stay-at-home Mom for most of my children's lives.  They've seen my attitude towards housekeeping and my skills in putting things off until the last minute.  And they have certainly picked up a LOT!!  And not in a good way.  Far too often, I have had the attitude of "me first, whatever I want to do, when I want to do it, who cares about anything else".  I recognize it now although for a lot of years I didn't.
So now, it's all coming back around to bite me in a very big way.  Our oldest son is in real danger of not graduating high school in May.  Brian may understand that, but I don't.  Brian had to do summer school in order to graduate because he didn't do so well in school.  I coasted through school, not really doing much and still came out with a B+ average.  We knew that Brandon was not a great student very early on.  I have been pushing and pushing and pushing the school district to help me for *years*.  They did testing- no learning disabilities.  Great IQ actually.  I've been pushing Brandon for years.  But it's not good enough.  He has picked up and learned my lazy attitude far too well.  He wants to go military.  We've emphasized that they won't take him without a diploma.  That seemed to spur him on enough for awhile.  Then he let things go again.  We tried bribing him with the promise of a new car (his dream car, no less).  That worked for about 2 weeks and then he let everything go again.  When he was younger, we tried pretty much everything we could to make him realize how important his school work was.  All to no avail.
So here I sit, after *another* row with him about his grades (1.50 GPA, 2 weeks into this trimester), feeling like a complete failure as a mother.  He went downstairs crying, I stayed upstairs crying.
So where do we go from here?  I want him to graduate.  I want him to have success.  I want him to be able to fulfill his dreams.  I want him to know how much I love him and want all of this for him because I love him.  I want him to understand I don't get mad about his grades because I think he's not good enough.  He is good enough!!  He's a very smart guy!!!!!   I *know* he's capable of far more than he shows.  He's creative, talented and so much like his Dad!!  I want the best for him.
I realize his learning style is not my fault.  It's just who he is.  I still feel like there is something I should have done.  Some character flaw in myself that I passed on to him through my actions and inactions.  If only I had done "that".  If only I had done "this".  If only, if only, if only.
If only I had the parenting instruction manual.  I try to do it like God.  He put Adam and Eve in the Garden.  He gave them the rules and the consequences of breaking the rules.  He left them to choose for themselves.  When they broke the rules, He immediately applied the consequences.  I've had partial success.  So I guess that means I've had partial failure too.  Right now it feels like complete failure.