BUT, he says if the clutch pedal can safely be modified so I can push with my heel rather than the ball of my foot, he would say OK to driving. I hopefully would need this changed back in 4-5 months. Any ideas?
Any trusted friends or family to exchange a car with for the duration?
Attach cane to said leg. Set cane tip on clutch pedal. When it’s push time, assist leg by, also, pushing cane with hand. This would make your leg handy, wouldn’t it?
If you don’t have big feet, try moving the seat forward just a bit & see if you can adjust to getting your heel up there to do it. I have a prosthesis on my left leg, so no ankle, much less ball to use.
Hire local area youth to work the pedals while you steer?
Sorry.
I like Andrew J’s idea of finding someone to trade cars with.
Yeah, but you gotta give a few points for hellokit’s “handy leg” idea.
Yeah steve thats what we need a driver pushing a cane with his left hand and shifting gears with his right. No hands on the wheel.
~Michael
There are shops that do “mobility systems” to adapt cars for use by drivers having such limitations. The pertinent example is brakes operated by a manual lever. There is standard hardware for that. (The shop I visited did jobs all the way up equiping vans with wheelchair lifts.) Perhaps such a shop can find a solution you can afford.
You wouldn’t need three hands (though, sometimes it would come in handy). Most of the exertion is on the PUSH, isn’t it? Perhaps you could HOLD with, only your left leg, switch left hand to steering wheel, shift with the right hand? If the left leg needs assist to rise, the left hand is now available. One could try.
Try depresssing the clutch with your crutch. If this doesn’t work, use both crutches. This is what we call “double crutching”.
Sure, an idea. Block of wood under your heel. A piece of wood fastened to the bottom of the block and parallel to the bottom of your foot. A couple of wooden side pieces on either side of your lower leg fastened securely to the block and the piece parallel to the bottom of your foot. A couple or three inexpensive plastic dog collars with quick disconnects to secure the apparatus to your leg. Use mending plates from a building supply store or a better method that you can come up with to connect the wooden parts intended to provide adequate strength. Plywood would be better than ordinary wood, of course. 3/4 inch thick plywood would be a good start.
A hand operated clutch in a vehicle other than a motorcycle could precipitate a disaster in a tight situation. By the way, can you ride a bike with an automatic transmission? There are a few. How about a scooter?
Don’t forget to take the fixture off or you will walk oddly.
The safest solution is obvious, of course, 4 wheel vehicle with automatic trans.
Please be aware that when you are making something new, failures are very possible and a little R& D may be in order. Hungry lawyers who can’t do these things but can second guess are watching.
If you must drive this car with a broked left foot shift without using the clutch. All cars these days have synchronize transmissions. If you time your shifting right you can go up and down through the gears without grinding gears. My mother used to do this routinly without any problems in the 1940"s. Usually if you shift either too soon or too late it simply won"t go into gear (although occasionally they will grind if your timing is only slightly off). You’ll still have to use the clutch when you start and stop the car (that when the “handy leg” indea would be helpful). It would be a shame to get rid of this car, especially if its paid for, because of a temporary condition.
Unless cane slips off pedal and that could be a big problem at a busy intersection. 
Many (35+) years ago an old girlfriend of mine had a 48 Plymouth with a standard shift. This car had heavy wooden blocks clamped to the clutch, brake, and accelerator pedals since she was only 4’10".
Both brake and clutch pedal blocks were oak, protruded down a few inches, and had an offset block on them that allowed the heel to do the work since this car required brute force to shift and brake. Think of them as thick L-shapes facing upwards.
Somewhat crude, but it worked; at least for her. It was a pain in the neck for me to drive, but it was stylin’ to say the least with one of Earl Schieb’s finest maroon paint jobs on it.