The truck is definitely not ideal but the real emergency here is the personal loan. The truck has already taken the big hit on depreciation at this point, another 6 months probably won't make too big of a difference and you need it for work, but that personal loan at 49%... yowza. My advice would be to spend every last cent (and then some! Use your spare time to make extra cash anyway you can) paying down that personal loan if you can't refinance, and you probably can't with your current situation.
That means making the minimum payment, plus the extra $300 you already know is leftover every month, PLUS everything you can save by cutting your expenses down to BARE BONES (housing, critical utilities only, child support, truck payment, and the smallest grocery budget you can handle), PLUS whatever extra money you can make by picking up side-gigs, overtime, doing favors for friends, getting creative, etc. Bare bones expenses really means you pay for nothing you don't need to survive or aren't legally obligated to pay for. No new clothes. No fun trips. No fancy dinners out. See what that leftover $300 turns into if you scale back as far as you can.
The loan only has $6,400 left and you make $100K a year. I have to think there is fat in your expenses that could be trimmed (that's why people are encouraging you to post a case study), and depending on how much fat, I think you can reasonably knock it out in 6 months.