Did you use extra firm or silken extra firm?

They aren't interchangable and it is really easy to read a recipe incorrectly. I made some very questionable foods when I first started using tofu.

Hope everything gets worked out with your pupper 💖

Some non-canned-tuna/spam suggestions:

Don't know how much you like tofu, but a box of 12 12oz tofu is like $23--Mori-Nu Silken Tofu, Extra Firm, 12.3 Ounce (Pack of 12) https://www.amazon.com/dp/B000LKZ86K/ref=cm_sw_r_cp_api_1Jfszb89GBXM8 Split it into 6oz portions.

Lentils are delicious. There's a Lebanese red lentil soup recipe I like, or I made a mujadara recipe using brown rice and green lentils and had enough servings for days. https://food52.com/recipes/67308-my-mujadara

Someone mentioned those Spice of India (or whatever, they come in yellow packages) and those are pretty good.

Almonds are one of my absolute favorite snacks.

Buy a bag of rice and that should keep you going for a while. Or pick up a different grain by Bob's Red Mill.

You can actually buy it on Amazon. I bought a bunch during the pandemic.

https://www.amazon.com/Mori-Nu-Silken-Tofu-Extra-Ounce/dp/B000LKZ86K/