The shadow home secretary told the Guardian she was diagnosed with the condition two years ago and it was "out of control" during the campaign, when she gave some faltering performances.
"During the election campaign, everything went crazy," she said.
She said she was managing the condition and was ready to get back to work.
Type 2 diabetes is a long-term condition that causes a person's blood sugar level to become too high.
It can be controlled by taking medication to reduce glucose to normal levels and also by making lifestyle and dietary changes.
Ms Abbott was criticised for her performance during the election campaign, in which she stumbled several times during interviews and appeared unable to give detailed answers to questions.
In one interview with LBC Radio, she mistakenly said plans to boost police numbers by 10,000 would cost Â£300,000. It led to a barrage of criticism from the Conservatives who said she could not "add up".
She pulled out of an interview on BBC's Woman's Hour with just a few minutes' notice amid unconfirmed reports that some within the party leadership had lost confidence in her.
Just 48 hours before polling day, Labour said Ms Abbott was taking a period of sick leave and would be replaced "indefinitely" by Lyn Brown.
Ms Abbott, a key ally and friend of Jeremy Corbyn, said she was badly affected after facing six or seven interviews in a row without eating enough food - vital to managing blood sugar levels.
"During the election campaign, everything went crazy - and the diabetes was out of control, the blood sugar was out of control," she said.
Ms Abbott, who was re-elected as MP for Hackney North and Stoke Newington with a majority of more than 30,000, accused her political opponents of mounting a "vicious" campaign against her.
She told the newspaper she was disappointed a female prime minister had singled her out as a national target.
The Guardian says a Conservative source "angrily rejected" Ms Abbott's accusations and said it was "legitimate in a campaign to point out weaknesses in the opposition's front bench"
The source wished Ms Abbott well with her health, adding: "No-one knows more about the difficulties of diabetes than the prime minister."
Theresa May revealed in 2013 that she had type 1 diabetes. During the election campaign she said she managed it by injecting herself with insulin six times a day.
Diabetes is a condition that causes a person's blood sugar to become too high.
More than three million people suffer from type 1 and and type 2 diabetes in the UK.
Diane Abbott has revealed she has Type 2 diabetes and that the condition is what forced her to take a break from the election campaign.