8BALL, first off, don't consider counseling. That's going to sound a bit contradictory coming from me since I do counseling as part of my post grad work, but I've seen many men in exactly your position and counseling is really last stop before toll. First off, it sounds like you can't afford it both time and moneywise, plus you'd have to regularly find childcare while you go and this only stresses her out while she's there. Secondly, you've already adequitely identified the problem, the next step is to initiate a change.
Remember, you will only get what you've gotten if you keep doing what you've done. The change has to come from you, you can't control her behavior, but you can prompt her by altering your own. As I stated before, start a takeaway, but do so in gradual steps. If you jump off the deep end immediately and turn off to her all at once she'll see it as a power grab and she'll recoil and hunker down to wait you out. When you incrementally pull back and stop doing what you've done to kiss her ass for so long, it will have a building effect. You want that anxiety to build for her rather than have it dumped on her at once. Women are much more susceptible to COVERT communication and sub-communications - Yes, especially your wife of 8+ years, she knows what to expect of you, so it works that much more effectively when you incrementally cease your prior behavior. Also bear in mind that you want to reinforce desired behavior, when she does become affectionate, reward it. The takeaway is behaviorism 101, reinforce desired behavior and/or do not reinforce, or punish, undesired behavior. You have to become the PRIZE again. Your attention must become valuable to her. Elements of an effective takeaway strategy:
Intitae it covertly, never overtly.
Create value through scarcity.
Communicate, but always say less than is necessary.
Stay in business mode - be matter of fact - never allow yourself to be perceived as sulking.
Conceal your intentions.
Reinforce desired behaviors, remove the reward for undesired behavior.
Make her come to you - anxiety is good for her and puts you back into a positive masculine role.
Make her dependent on you for her own affirmation once your attention becomes valuable to her again.
Re-create yourself and remake your identity and become someone who she has genuine desire for. I understand that a lot of this will be hard to swallow since it will seem counterintuitive to getting what you want, but it's really for the best - even if you do divorce her at the end of it all, you'll be on better self-confidence footing when you do go out with other girls later. You're not getting any less sex or respect than you are now by starting a takeaway.
Also, get in the gym and transform your body NOW. Nothing will send a message quicker than simutaneously looking better and intiating a takeaway. This is one of the most blatant, tell-tale signs that a partner is preparing to leave the other. Women do this all the time, they hit the gym like animals because they've already decided to eject from the relationship. They'll of course deny it to the grave, but the behavior belies the intent after the fact. That might seem hard to do with your work/family schedule, but find a way. Go at 5am if you have to.
Now, all that said, if it turns out she's too far gone and you have no other recourse but to divorce, prepare yourself for that too. Go see a lawyer well BEFORE you draw up papers. A little bit of preparation 6 months to a year before a divorce will save you all kinds of personal and financial woes later. There are divorce attorneys who specialize in exactly this kind of planning. Divorces are expensive so don't jump out with your pants down.
From a personal standpoint, you mentioned 2 reasons for staying in the marriage; your kids and your debt. First, bear in mind that you are far more likely to incur more debt married than you will divorced. Things come up all the time that will forestall you becoming debt free, kids get sick, cars breakdown, the house needs a new roof, etc. You being in debt single will limit the occurances of more debt. You can argue child support as well, but you're essentially paying that now. You and your wife are already divorced from a relationship standard, and are sharing custody of your kids, you just happen to co-habitate together for financial reasons.
As far as your sons are concerned, yes, raising them in a two parent family is ideal. Raising them under the conditions of her setting and controlling the frame for you in your home is detrimental to their understanding of gender roles however. I've seen countless men stay in a miserable marriage "for the kids", but it only contributes to these kids having skewed understandings of gender role. You are setting the understanding for your sons of how a man behaves and thinks, and likewise your wife is creating the role of how women are. Is this the understanding you'd like them to go through life holding to? If you do stay together for your kids, do something different NOW. The first 5-7 years of a kid's life develop ideals and understandings more than you can imagine.