Yes, keep plugging away at the TSP. It's probably the best 401(k) plan out there and contributions could help you qualify for the Earned Income Tax Credit.
How much are you saving/investing in an average month?
Your Internet bill seems high. Do you need the speed that you're paying for? Could you get a slower speed for less? Do you need the alarm system? I think the best deterrent is the alarm company sign outside the house.
I don't know if I'd sell the new car, honestly. The Sinata loan is for practically no interest. It could last until your children learn to drive. I may be in the minority here on that. But if you bought it new, it depreciated so much already. Getting a new car last year wasn't the best choice, but I'd consider keeping the car now. It gets good mileage and is a safe car for the kids.
As for the Jeep, how much is going into repairs? My wife has a 1998 Jeep Cherokee, and it's still running pretty well. However, if you don't need it, why keep it?
I assume you're the only worker because our children as young. Before you know it, your kids can be at school and your family's income can dramatically increase.