It's hard to know from what you wrote how far off track your son is. Most teens challenge us, and yes, leaving them alone to their own devices is a bad idea if they can't be trusted. So I loved the gal who suggested a babysitter. That is a natural consequence to his actions. He will scream, "You don't trust me,".......which of course is true, so you can just tell him you love him. Now, if he is truly "always" in trouble then you may need to take a few extra steps to get him in line. Depending on how bad it is:
#1-Read the Love and Logic Books. They will help you know appropriate consequences and how to avoid anger.
#2-Carefully monitor where he is and who he is with. He won't like this of course.
#3-Figure out if he is struggling in school because it is hard for him (an un-diagnosed learning difference) or whether he just doesn't care. Consider changing schools, getting him tutoring if it is difficult. Help him by offering positive incentives if he does well rather than scolding him if he does poorly. If it is that he doesn't care, why? Talk to him. Tell him you love him and want him to do well in life. Tell him why you think school is important and let him know you want to help him, but don't lecture him. If he does poorly be sorry for him, but don't act disappointed IN him.
#4-If he isn't in any club or activity, encourage one. Be sure to find something he CAN excel at. Be it sports, playing a guitar, a video game champ.......encourage a video club at your house if you have to. This will keep him home where you can keep an eye.
#5-If he is truly out of your control then seek intervention. I did a google search and came up with this website: http://www.focusas.com/Texas.html
As far as your marriage. If you can afford it a little family counseling could go a long way. 1-3 visits could make a huge difference. Talk to someone at your place of worship if money is tight.
Hang in there. I'm sure your son is worth it! Most teenagers challenge their parents. The most trusted kids seem to slip a little in their teens. You might tell your boy that you know how hard it is to be a teen, but that you will help him and it will get better.