No biggie at all! Let me put it this way; before my last trip (trips always drag my level down anyway and recouping from a stroke while down there, so no clue yet of my current level) my standard level was >20 hours a day bedridden and those other hours fully wheelchair dependant.
I've done all kinds of trips, incl. WDW -which for me is a transatlantic trip- as a solo and do perfectly fine. Heck, no clue yet about my new level but a next trip is booked again as solo and will happen. You should see me at the airport, you would have a difficult time not lauging.

One little lady, a manual wheelchair, powerchair, 4 checked full sized bags, 3 regular sized carry ons, 2 check in sized carry ons, and a bag or 2 with wheelchair parts. Oh and can't lift anything over 4 pounds. Yet I get where ever I need and want to with all of that junk. For those curious minds; no I do not need that much clothes or make up.
It's mostly a mindset thing and taking use of services there are. Focus on how you CAN do thing or CAN get them done instead of focus on what might not be or how something can not be done.
Getting to the airport; either get a friend or loved on to get you there would eliminate dragging luggage yourself to car. From car on; airport assistance if you need ir for the distance (prebook it through airline!!) and porter for your bag. Tip accordingly and you will soon find your bag checked and you on the plane.
Check out the TSA-website if you want more info about doing the security check with footie-ouch.

It's pretty self-explaining, esp. with something so normal and common as breaking a limb.
For the flight; do make sure you have the right cast (not all are safe at all times after a break for flying) with your doc. Make sure you can actually sit as needed. Shouldn't be a problem with a break in a foot and being able to bend your knee, but if you find you do sit differently; make sure!
Getting of the flight; you can let DME take care of the luggage. Need carry on? Travel as light as possible -and that can be done very light- but if need be; don't make it an accident waiting to happen and get assistance if need be. If need be, let them push you in a chair while you take care of the bag, or you use your crutches while they take care of the carry on. For whatever reason absolutely need to get the checked in bagage yourself? Again, there are porters just for that. No need to even risk breaking a nail, so to say.

Been there done that, always pick them up nowadays since DME no longer sents the tags to our side of the ocean.
If you can navigate stairs, DME is no biggie for you. Stairs a biggie? Contact DME beforehand about needing a lift. The busses now all apparently have lifts, which makes it A LOT easier, but still. Reconfirm at check in with DME. Use the lift with wheelchair to get onboard, then proceed to seat. Reverse at resort.
How far can you navigate on crutches on a busy long day? Is that still enough to reach the furthest out room at your resort easily? If not; make sure you have a reservation for an
ECV and one where you can have the ECV waiting for you at the resort. Go to bell services first for that, then check in while using ECV and no more risk of falling because you overdid it.
Parks -> ECV. Pretty self explaining. Read up on the stickies on here and you know much more than you ever reckoned you would. Do yourself a huge pleasure and take along a bit of rope, tape or alike to be able to secure your crutches safely (for both you and others!!!) to the ECV but at the same time being able to remove them and use them for instance for transfers onto rides.
If you can navigate those lines needing you to transfer to a manual chair by using either crutches or navigating the chair yourself (pretty hard work!!), there is pretty much nothing you can't do. Those might be challenging, read undoable otherwise. Some rides will find you needing some time to work out how to do your transfer being new to it all, but so be it. If need be; practice a bit at home getting yourself transfered to and from. You've done enough rides as a member to know a bit of what to expect getting into and out of seats, so that will help a lot knowing which moves to expect more or less.
Bags; get them put in room by bell services. They are more then happy to put them where ever you want them to make unpacking possible without risking a fall or something.
It's new and that can be scary. But, with a bit of a positive and can-do-attitude, you will find this is a different trip but doesn't nearly have to be a mwah, let alone bad one.
Flight shouldn't be so long that you'ld need to get up, but if so; factor in risk of unexpected turbulence. Best way of protecting is to use what is there already; support yourself not just with crutches, but secure even more by knowing where the seats are, walls are etc. Bathroom is very small, but that's a good thing. No space to fall far.

Seriously though, those walls so close is great to literally brace and secure yourself between the right and left wall with both arms and have a perfectly staying put all around set of crutches. Can be used to get on and off the toiletseat. Don't close or open door unless seated, is lots safer. If you need your bag; poor planning most of the times. Have on your body what you need in flight. If too much for easily getting around airport; get it from your bag before having it stored in the bin after boarding the plane. Storing can be done both by assitance, flight crew and many times passengers around tend to offer when seeing someone is incapable because of physical limitations. I find having my stuff ON me, thus requiring nobody's need in flight works best for me. No need for asking, no possible wait etc. The attendants don't mind if you ask not that many times and bag isn't breaking their back, but I like being prepared with that little I do need while in flight.