The 25-year-old former Celebrity Big Brother winner and Geordie Shore cast member was stopped for driving erratically in Newcastle in January.
The city's magistrates heard she had earlier been drinking on a train home from London to Tyneside.
The court heard the conviction would scupper plans for a career in the US.
Crosby, who admitted the charge, was also ordered to pay Â£1,185.
Magistrates were told Crosby's Range Rover was seen weaving down the road by two police officers in the early hours of 28 January.
When she was pulled over, a breath test showed she had 80 microgrammes of alcohol in 100 millilitres of breath, compared with the legal limit of 35.
The court heard because she also had been banned from driving for 18 months in 2012, she would not be able to get a visa to travel to the United States, where she had planned to work.
Nick Freeman, defending, said Crosby had decided to make the short journey from the railway station to her hotel despite having initially planned to get a taxi.
He said: "She accepts that she is the author of her misfortune and is bitterly ashamed, contrite and embarrassed."
He added his client had been close to landing a TV career in America but "that will not now happen as she will not get a visa".
Banning Crosby, chairman of the bench Keith McIntosh said it "beggared belief" that she had been caught for a second time.
"We take drink-driving offences very seriously in this court, even more so when it's not the first offence," he said.
Crosby, from Sunderland, won Celebrity Big Brother in 2013 and appeared in all 11 series of Geordie Shore.

The 69-year-old man was cut free from his white Ford Transit van after the collision on the southbound carriageway at Cilfynydd at 12:25 BST.
The Wales Air Ambulance was called and the road was closed in both directions, causing delays between the Abercynon roundabout and Pontypridd town centre.
The man is in a "stable condition".
The northbound carriageway of the A470 re-opened at about 14:05 while the southbound lanes opened at about 18:20.
Reality TV star Charlotte Crosby has been banned from driving for three years after being convicted of a second drink-driving offence.
[NEXT_CONCEPT]
A man is in hospital with serious injuries following a crash between a lorry and a van on the A470 in Rhondda Cynon Taff.