Illness will throw you right off track. Don't blame yourself for feeling down and unable to eat properly.
I had a recent massive allergic attack which threw my immune system off kilter and triggered all sorts of minor viruses which, in turn, set off my asthma. The complaints and the cures (strong steroids for a while) kept me feeling alien in my own body and I knew I was putting on pounds and losing my level of fitness.
As I have got better, and after a course of antibiotics for the inevitable infection caused by all the shenanigans, I am back to strength. It has taken time and reassuring myself that things would return to normal.
I gradually felt myself again and was able to resume walking and my usual regime.
As for the extra eating, I set short term time goals, for example, in the mid morning I'd decide not to have anything until 12.30 and, to get there, I'd distract myself by ironing a few shirts and listen to Radio Four 'Catch-Up' while doing so.
Or it can be done the other way around. Say, 'if I can last 3/4 hour without eating I can have an apple or 20 nuts n' raisins.' Either works.
You will get better and on top of things. It takes time.