I recently considered following a vegan diet, but haven't made it that far yet. That was one of my questions: what do vegan's need to perform athletically? There are some very successful vegan endurance athletes. I just googled some, and skimmed a few articles. So, it can be done. Even with meat as animal proteins, I know the feeling you are describing well. Like omg my jaw is actually tired of chewing, my stomach feels like I'm first trimester prego, yet I'm starving to death.

Seems like what I did when I trained for my century was to make sure I also ate and drank well on the shorter rides. Our physical activity and diet are accumulative remember. I think it helped. OK, I know this won't help you because it's meat, but one of my best recovery meals that stopped the starving sensation was: whole wheat spagetti (not just brown noodles, the kind with the most fiber possible), marinia sauce, and grilled chicken breast w parm cheese. And something about a lime Edy's juice popsicle for dessert made eating life all better lol. (maybe you can figure out the grams of protein in the chicken and come up with a vegan subs w similiar protein- black beans?).

You could also get an appointment with a sports nutritionist. I saw one once and it was educational (besides books I own, and TE of course). Hope you find some resovle!