Speaking after the Human Fertilisation and Embryology Authority confirmed its original ban on allowing her to have artificial insemination treatment using her dead husband's sperm, Mrs Blood, 30, accused the HFEA of "mental torture".
She said she had not yet been given reasons for the decision: "I think it is incredibly cruel. It really amounts to mental torture.
"When they said they were going to reconsider I said I was cautiously hopeful. Everybody else was probably more hopeful than me. They must have known what they were reconsidering, so why did they raise my hopes only to dash them in an incredibly cruel manner?"
Mrs Blood had hoped that the authority, after reviewing her case, might use its discretion under the law to give permission for her to have artificial insemination outside the UK.
Last night after she was turned down she held a news conference at a pub near her home in Worksop, Nottinghamshire, and said: "I was very distraught not only at this news but also with the way I seem to have been treated within the last 24 hours. I will take this fight as far as it needs to go. I have got a date for my [Court of Appeal hearing] in January next year."
Mrs Blood's father, Michael McMahon, said: "She was very hopeful because of the public backing for her. She's obviously very, very knocked back." .
The authority said it would give its reasons for maintaining the original decision after they had been properly communicated in writing to Mrs Blood. In the wake of widespread public backing for the 30-year-old widow, the authority had been reviewing all the evidence in a High Court case last month.
It had made its original decision to ban the use or export of the sperm without considering a range of submissions in support of Mrs Blood's case, including a statement from Baroness Warnock, who chaired the inquiry that preceded the 1990 Human Fertilisation and Embryology Act.
Sir Stephen Brown, President of the Family Division, declined to interfere with the authority's decision to ban artificial insemination with the sperm because Mrs Blood's husband Stephen had not signed a consent form before he died, as specified in the Act and directions made under it.
The sperm was taken from 30-year-old Stephen Blood when he was lying in a coma after contracting meningitis.
Anne Campbell, the Labour MP for Cambridge, this week introduced a backbench bill to change the law. Mrs Campbell said: "It would not be retrospective so it would not help Mrs Blood but it seems to me that the onus should be on the woman to prove that her husband wanted the sperm to be used, rather than in Mrs Blood's case where they have denied her any chance."Reuse content