Whooo. My brain. That truck payment.
Well, I understand it isn't your fault, so no facepunches here :). You might suggest keeping 3-6 months worth of truck payments as a "truck emergency fund" so that, given a setback, he could keep the truck and not be getting calls from the lender or get it repo'd. If he needs to see emergency savings from that perspective, then do it. It may even trigger something in him to realize just how expensive that is, and he may see it as you being supportive of him in his...er...love of alpha status? Gosh, I can't believe I'm saying this, but I hear getting a spouse on board takes time and cunning. (as a single person, that truck payment is slightly higher than my rent, utilities, car insurance, and cell phone COMBINED)
The good news is that those lessons/therapy are scheduled to end soon, and that will free up a lot of money. But be talking to your husband now about what you two will do with that money when it's free, or he may make up his mind without you. Just sayin'. Start the conversation now so that when the time comes, that money will be going to a good place (savings, paying off debt, etc)