Trading one inefficiency for another?
As you said, your last trip was not really an efficient use of your time (though you got a heck of a lot of ground covered). And whereas I agree with Dave that the outline is doable, you could be trading off one inefficiency for another.
Depending on what your interests are, and to what extend your disability affects your travels, have you though of including some of the places to which Dave alluded? You might find you will get to see more, cover fewer miles and not be so rushed, if you created a loop trip. It could also save quite a bit on air fares and car rental.
Once we know more of your interests and the sort of places you would like to visit, such a trip would be easy to put together.
BTW - I had to smile that you are already planning to come back. It gets addictive. :)
Lifey