The lender either knows what is going on and isn't telling you or they're incompetent. Simple. Either way, not good for you
Another piece of good news: USDA turn times here locally are 16 BUSINESS days. Those turn times vary from state to state. Even when/if it gets to USDA, you still have a long way to go.
You are finding that out the hard way.
Perhaps you should reach out to a real estate attorney as it's a little late for help from a realtor now.....I am not being rude, but selling a home on your own takes real preparation and knowledge of the entire process - not just a sign in the yard......you need to be informed about the potential problems that could occur.
Of course you're a wreck - you have no one to turn to who is on your side or guiding you.
I wish you good luck, and I hope it turns out well for you.
ps there were times I wanted to put my "son in the yard", too, and I wasn't selling a house!