You can try entering a "0" for your AGI, sometimes that works, if you haven't already been there done that.
Failing that, you should file a paper return - print it out and mail it in. Sometimes the IRS keeps rejecting because it doesn't match what's in their database through no fault of your own.
Your electronic payment will NOT go through if your efile doesn't go through. Instead, go directly to the IRS site irs.gov/pay > choose Pay Your Taxes Now > select Bank Account/Direct Pay which is free (the card option charges a fee) and follow the instructions.
Your payment might not go through until tomorrow or even later, but as long as you SUBMIT payment by midnight you'll be fine - you won't get hit with late penalties.