I am so right there with you. December has been the absolute worst eating month for Alexander ever. Yesterday, for the ENTIRE DAY, he ate a chicken nugget and 3 segments of a clementine. And that was it. I also broke down and cried several times this month. I know exactly how much pressure is on us to get these kids to eat since they are below the weight chart. I know that A is the same weight as he was at 18 months and I am going to totally get sh!t for it in 3 weeks when we go to his 2 yr checkup.
One thing that has worked for us SOMETIMES is putting food directly into his hand. Sometimes he looks down and is like, Oh, I must have picked that up, and then he eats it. Weirdo.
Let me know if you want to talk (PM me). I feel like you and I have a lot of the same pressures since weight has always been an issue with our guys.
ETA: And I totally understand the "eating crap is better than nothing". I know it's not right, but when your kid is literally eating nothing, you feel like they are going to die. So you are like, "Well, this cookie has an egg in it..." I mean absolutely no offense to bumpies who say they never give junk food even when kids don't eat, but I don't think they have kids who are literally eating nothing the whole day.