Tips for healthy weight-loss with a 50hr work week.

Wow, you do have a busy schedule, but you are fitting in the walking, that is great exercise and it may be all that is realistic right now.
Focus on your food first, don't reduce your calories any more but try to eat the healthiest range of foods that you can manage within your budget.
Remember that MFP has already created a calorie deficit when it calculates your daily calorie allowance so you can lose weight without exercise if you have to.
I would keep going with eating well and just the walking for a few weeks, then if you can manage it, try to get up 20 mins earlier a few times a week so you can fit in a short workout.
You don't have to exercise for hours every day to lose weight and be healthy and when you don't have a lot of time to spare you have to smart about what you do.

may consider ankle/wrist weights.. that way you can do strength training stuff on your walk. I dont know the cost of them, but maybe you can find a good pair on craigslist or ebay or something. Just a thought, but if you had wrist weights you can do arm curls or something on your walk to boost your walks a little

I also work 2+ jobs (more depending on the week/season) and understand how exhausting it can be.
Instead of taking your calories to such a low number, especially if you're walking and on your feet for so much of the day, perhaps just being more aware of where those calories are coming from would be more beneficial. Make sure you are getting plenty of protein and not turning to sugar (or starches!) to find your energy.

This may be hard to believe, especially as you're just starting this hectic schedule, but I have more energy through the week when I get my gym time in. When I was in grad school and working several part time jobs, I didn't make time for working out. Not only did my body suffer (I gained 15 lbs that year!!) but I was exhausted. Now that I'm used to working out, I can totally tell when I've been slacking off or too busy to squeeze it in bc my energy lags.

So, how to fit it in? Some people will look at your schedule and suggest morning time. If this works for you, great. It never has for me. I do everything I can at night so I can catch that extra 5 minutes in the morning. I'm just not a morning person.
Do you have any time during your day job that you can incorporate more walking? Maybe a short walk on your lunch break? In 20 minutes you could burn an extra 100 calories (give or take a few). Plus it would give you a little extra stress relief and fresh air to perk you back up for the rest of the long day.
I've been blessed enough to have free gym membership (thanks to one of my part-time jobs!) at the local Y and it's open til 10... I close it down many nights. I'm sure to pack a change of clothes and a snack when I head to my second job and go straight there when I'm finished. Usually in winter, I keep a bag with a change of clothes in my car in case I somehow find myself with an extra 30 minutes and head to the gym without needing to run home. For a little while I had membership at a 24hr place-- this was great! I'm sure most big cities have them.

NOTE- if you're too tired for intense cardio and you're doing all your walking, try weight lifting!

If the gym isn't an option, try adding in some body strength moves at home-- these don't have to be done at any specific time (morning or night) but if this is the route you decide to follow, make sure you plan when you're going to do them and then stick with it! Great moves for this include push-ups, lunges, squats, etc. If you stick with doing those, maybe invest in some hand weights to add other moves that you can do anytime.

It is possible. You just have to be creative! Decide you are going to do it. Once you get used to it, it will help you power through your long hours!

My advice, to be honest, would be to focus on diet ahead of exercise. It's perfectly possible to lose weight through diet alone, and damn hard to lose it through exercise alone, and if you have a hectic schedule you'll have real trouble fitting in loads of exercise on top of everything else. Instead, I'd say, maximise your opportunities in terms of your walks (e.g. up the pace) - this way you're saving the bus fare and getting in your exercise at the same time - and, although your shopping choices are limited, try to focus on your food choices as far as you're able.

I travel 2-3 days a week for work, and 50-60 hours a week, and weight loss is TOUGH! I always keep healthy snacks with me, so that when I get hungry, I don't run to the vending machine. I also have a Pedometer watch from Walmart for $34, and make the 10K steps a day mandatory, even if that means I have to run around in my hotel room at night. Good luck, we can do this :-)

Let us know how you are doing on steps. 12,120 for me today. I talk to my mom on the phone as I walk (58 min, today) so I can do two things at once which helps me justify an hour of not doing work, housework, homework, etc. But remember, you don't have to do 60 minutes in a row - 10 min here and 20 min there adds up over the course of the day. My mom just put her pedometer on today for the first day-proud of her!

Your situps and pushups are impressive. I could only do 2 pushups when I started.

Keep logging!