Animal Pak: they've expanded their line, but the original products are essentially expensive multivitamins. However, their website rules and I buy shirts and crap from them just to support their policy. My avatar is actually from a picture in their "Journey" collage.
Until you get access to a gym, do
this.
Finally,
zig-zagging should be more bearable for someone your size. You do need an appropriate amount of calories to prevent muscle catabolism.
Oh, and if you want credentials, the frail-looking professor at the top of that article set a powerlifting record when he squatted 1,014 pounds.