Since you mainly need him to eat right now, consider some of the cheap food they love like Caesar's or top with grated cheese.
Warming it up a little often helps, and so does handfeeding. Gizmo will often get hungry after eating a few hand fed to him. I have to fling a few in the air and then he starts playing and eating.
Yogurt helps and cottage cheese too.
Vitamin K is really important though. Vital really. Gizmo had injections and then a pill to take every day. If you're not doing that, you need to contact your vet asap.
Poor baby!
