I don't know who needs more advice here, you or your husband. Let's start with your husband. This is his third internet business, which has already depleted you guys of all your $$, has no chance whatsoever of making any money at this point, let alone be successful, but yet it is his third attempt. I assume the first and second didn't really do well, either, otherwise he wouldn't be giving it a third try.
Your husband is walking around in a daze because he still cannot accept the reality of being a failure at his business. It almost sounds like he's in some sort of shock, or something. Now, he is in a position where he has to work. But the no-degree or the failed business are just plain excuses. He hasn't looked, either, you say. It's about time he just gets out there.....no excuses. He might not get the best paying job, but attitude is everything. He's gotta get rid of the I'm no good, no-one will hire me attitude. Because if he doesn't, then no-one WILL hire him.
Now, about you: Congratulations on your PhD!! Achieving that is incredibly difficult....how much longer are you going to support this man?? In any marriage, it takes hard work, communication and support of each other. But your support is very different from most women....you'll do anything for this guy...and keep on doing whatever it takes to make him happy. But by doing so, you are continuously hurting any chances of him feeling really good about himself. In other words, the more you offer to help, the less likely he is going to be able to stand on his own two feet.
You work all day, you have no social life, and your husband is a zombie. You are going to get your degree and yet you are so focused on him, him, him. What about you?? You've worked so hard....now it's his turn!!!! Time for him to get up, get on his own, and give up the business. Do NOT even THINK that you'd help him find $$ to continue this so-called business. If he decides to pursue it further, so be it, but this time he should go to a BANK!!!!
You can't tell him what to do, but you CAN tell him how much more you'll put up with. If he doesn't talk, then he can't communicate with you. You've done enough for him...now concentrate on you. Tell your husband you're taking off for a couple hours to spend time with family or friends. Take off for a day or two and get away from him. Maybe some time alone will knock some sense into him. Best of luck.