I do not want to pay for anything she has now, but my kids make me feel like I am just being mean or revengful if I cancel her phone or try to get the jeep back.
I want to file for divorce it don't have the money to get a lawyer.
The best time to get divorced is when you can't afford it! You have nothing more to lose. Imagine if you had $1million in the bank, a high paying job as a banker, and a new Ferrari. You'd certainly feel you had a lot to lose in divorce.
Financial reality is what it is. You cannot afford to pay for her toys right now. Were you a dentist with no debt, yeah you could afford to pay for her car and phone. But you're not, so you can't.
There is no shame or fault in you not paying for those things.
I would stop paying for her phone today. Tell her she has 48 hours to change her phone to her own name. If she isn't off of your plan by then, you'll cancel it off of yours.
If you can legally take the car, I would go do it. This may be a tricky thing if she is a joint owner. You can't knock her to the ground as if she were a thief. But you can go with your set of keys and drive it away peaceably. I would do some internet searching to see if this is legal in your state. If so, I would retrieve the car and sell it to pay off the loan. If you're not upside down in it, a used car lot might give you enough cash on the spot to pay it off. Selling it privately might be less convenient but bring you more money.
Or, you could tell her she has to finance it in her own name within one week. Either she finances it or you are selling it. When she does finance it, you sign over the title to her, and you cancel your insurance on it.