Former president Bill Clinton said he could not sleep for two years after the 2016 election, which his wife Hillary Clinton lost to Donald Trump. Clinton makes the admission in his new book, Citizen—My Life After the White House, according to the Daily Mail.

“The whole thing is hard for me to write,” the former president writes. “I couldn’t sleep for two years after the election. I was so angry, I wasn’t fit to be around. I apologize to all those who endured my outbursts of rage, which lasted for years and bothered or bored people who thought it pointless to rehash things that couldn’t be changed.”

Clinton also writes that he concurs with professor and author Kathleen Hall Jamieson’s belief that James Comey’s announcement that he was reopening the investigation into Hillary Clinton’s emails days before the election coupled with Russian cyber attacks were, as Clinton writes, “effective enough to persuade voters in Michigan, Pennsylvania, and Wisconsin to vote for third parties or stay at home. If so, Putin’s enablers were Comey and the political press.” Read more at the Daily Mail.