Reality checks are painful, both physically and psychologically. Based on what you posted here and in your gofundme posts, you started March 15 and got off the trail roughly July 18. You went 750 miles in 125 days, averaging 6 mpd (miles per day). Yes, I know there were foot problems, gear swap outs, and weather delays. Most hikers experience some, if not all of these to some degree. But the reality is still 6 mpd (miles per day). Ask yourself, "did we spend 60+ zero days because of foot problems and weather?" Because a 12mpd average is pretty much a bare MINIMUM for successfully thru-hiking in a single season.
Please consider that the trail will NOT get easier in the north and that goes doubleplus for Maine and New Hampshire, where your daily mileage will drop due to difficulty of the terrain, possible bad weather at higher elevations, and logistics of where you can resupply and camp.
I don't think the car plan will work, especially starting SOBO at Katahdin. You'll be spending both precious time AND money moving the car around, and Maine is likely not a place you'll likely even break even on gas money. You'll spend more money fueling AND more time driving the car around (and NOT hiking) than you'll take in. How would people even contact you for services given the spotty at best cell service? Then add in the possibility of a car breaking down and requiring repairs in a remote section of Maine - when you are on a razor thin budget. By the time you get back on the trail, even if just a week from now, Maine's realistic summer will be almost over (Labor Day, Sept 6), and daylight hiking hours will start getting much shorter, especially in ME and NH. The weather will start to turn as well, with cold rain and even frozen precipitation at higher elevations in the Whites as early as mid-September. Later season NOBO thru-hikers will be going the opposite direction from you, and within a few weeks they'll all be well north of you. I don't see them needing shuttle rides or such anyway - they'll likely have resupply and other such needs already planned for.
Given your prior history in regards to average pace, the increased difficulty of terrain, seasonal weather and daylight changes, potential for foot problems, etc., I just don't see you completing this hike this year. Hey, you hiked 750 miles. You are part of the very large majority of people who planned to thru-hike and never completed their thru-hike due to a myriad of reasons, and running out of money is a common one. You made it farther than most people do. And you can always go back and finish, either in a single season or over multiple years.