WASHINGTON (TIP): At times, appearing impatient but never losing control of self, Hillary Clinton answered questions at a nearly 11-hour congressional hearing Thursday, October 22. The Congressional hearing was dominated by Republican criticism of her response to the Benghazi attacks. After a day-long grilling on the details of the attack and how Clinton handled it, the former secretary of state was forced to defend her use of a private email account while in office from a flurry of late evening attacks by GOP lawmakers.

CNN reports that she also came under testy cross-examination over the extent to which she has taken responsibility for the deaths of the Americans in the September 11, 2012, attacks and her contact with U.S. Ambassador to Libya Chris Stevens, one of the victims, after sending him to the North African country.

“I came here because I said I would. And I’ve done everything I know to do, as have the people with whom I worked, to try to answer your questions. I cannot do any more than that,” Clinton said towards the end of the grueling day — before later breaking into a coughing fit and taking a throat lozenge to ease her failing voice.

One of the most dramatic moments of the hearing came when Clinton was asked about her contact with Stevens. She acknowledged that she couldn’t recall having talked to him after having sworn him in as ambassador, though she believed they had spoken.

Despite the day’s intensity, Clinton appeared cool and in command for much of the hearing. But as the day wore on, she seemed to be increasingly impatient with the Republican line of questioning and with the constant interruptions from the GOP members on the panel.

In her most emotive testimony, Clinton sought to defang the GOP attacks by arguing that she was agonized over the deaths of four Americans in Libya more than anyone else on the panel.

“I would imagine I have thought more about what happened than all of you put together,” she said. “I have lost more sleep than all of you put together. I have been wracking my brain about what more could have been done or should have been done.”

Clinton noted that an independent Accountability Review Board that she set up as secretary had pulled no punches, unveiling 29 recommendations for improving security for U.S. diplomats overseas. She also noted that previous attacks on Americans abroad, including in 1983 on a U.S. Marines barracks and the U.S. Embassy in Beirut, had produced changes to U.S. security procedures after nonpartisan investigations by Congress.