If you cant fix things as suggested. Pretty drastic ,but there are other alternatives.
You can dismiss troops, you can attack on a suicide mission, or get someone to attack your town, the last alternative is the best, as I am pretty sure that sick troops eat nothing.
N.B. Of course you need infirmaries to cover them.
Aside from that, can you forge any hero equipment that increases food production?
If you only have farms then you are going to have to take drastic measures, because you cant level up without the other buildings.
I do not know what your development is, but are you sure you need troops you cant feed properly at the level you are at now.?
You have a maximum numbers on march, and a certain amount of marches, so I wouldnt think you need more troops than you can send out at the same time.
I had to go back and check how many resource buildings you can have(25), so you should still have your other resources buildings.
You could get ready to upgrade the palace with everything you need apart from the food, then hopefully you can go for some food from tiles, and hope there is enough to start the build before the troops eat everything, and work your way out this way.
Another way you can get instant food is do not claim your high value food tasks when they are complete,wait till you can start the next palace level, then claim them.