I think the thing to do is figure out how to make things you like quickly so you can control the sodium yourself.
Some things I can make pretty quickly are: broiled flank/flat iron/skirt steak. Season with salt, pepper, garlic powder, pop it under the broiler for 5 or 6 minutes each side, let rest for 6 or 8 minutes, slice (slice against the grain in skirt steak) and enjoy.
You can also broil tilapia following a similar method. I like to spray it with olive oil using my Misto, season with salt pepper and dill, and leave it under the broiler for 3 to 4 minutes on each side. Good stuff!
I know you're looking for microwave meals, but I think you might enjoy your own food even better, and you can get a nice meal on the table in 15 minutes if you're making the right stuff.
I also recommend the frozen veggies you can microwave in the bag. I like to serve those right out of the bag.
DISCLAIMER: I expect to lose this weight over the next 6 months to 5 years. I'm not going to feel like a failure if it takes an entire month to lose 1 pound. I'm going to feel like a success when that happens! I may offer advice that I'm currently not taking myself. Feel free to call me on that!