The Empire of DACU has 345000 soldiers. If you had max forts and some bases you would have ~180k or less. This means you have a few weapons and that number has been increasing as your soldiers are up in recent months. Any ammo using weapon uses up ammo every month. Your country will place orders to replace this ammo and this cost does not show on monthly expenses. You monthly profit is also thin to pay for this.
I would recommend a few things. First, recognize that your main country cannot be attacked in secured mode, even if you raise your war level to 3, and reconsider your forts and any weapons there. Second, improve your profits. Start by working on your welfare index. Check the docs for its calculation. You should look to raise it above 130. Start with your education index.