definitely doable. You job may not pay much but at least your expenses will be low now. Direct it to the essentials, a bed in your jeep, a way to store stuff, cook food, privacy, a way to use the bathroom and shower.
bed: you can get an air mattress real cheap at walmart, like 8-15 bucks. Find some discarded plywood or buy a sheet of 'top sheet' osb plywood for $5-6 bucks at lowes (these are off pieces they use on top of the nicer wood to protect them, usually completely painted on one side and stacked outside). See how much room you have for bed, folding seats down and moving front passenger seat all the way up. Have them cut the board for you. you can cut it into smaller pieces and buy cheap hinges to make it fold up when not in use.
Bathrooms: Use public for now, shower at truck stops. If its still warm there you can grab a 10 dollar solar shower from wally and go to a park to use it. Upgrade to a gym membership when you can. Id get a pee bottle for emergencies, kitter litter bottle at DG for 3 bucks with wide opening work good. Get some baby wipes too for freshups between showers.
Food: I lived for 4 months on essentially 250 bucks once, it wasn't fun but I found spaghetti with chucky sauce (no added meat) is really cheap and stretches far, and the sauce keeps for a long time. Eggs can last 2 weeks unrefrigerated, bag of potatoes.
-Grab a cheap camping stove. Go to a park and grab a picnic table to make meals. Enjoy nature while being frugal. The less you eat out the more you can budget for other essentials. Hit up a dollar store and grab 2 spray bottles, fill one with soapy water with some rubbing alcohol mixed in, and plain water in the other for cleaning dishes, your hands, your bum whatever
You probably already have a frying pan and a pot but if not, thrift stores are a good place to go.
Privacy: Go to dollar general to the section with posterboards, and there is a black foam board there. Buy enough of it to cover all your windows. Cut them to match the window but slightly bigger so they need to be pressed in. From outside it will look like tint at casual glance. for the front windshield, just a sun shield which isn't too out of place.
Longer term goals: Get a $40
roof top luggage bag for your jeep. They hold a surprising amount of stuff and will really clear out space for you and wont look too out of place on a jeep. after you have the essentials start sacking away money, even if its only a little at a time. This will give you more options for an upgrade.
Maybe a small cargo trailer to pull behind the jeep.