“I feel like someone who has been put on death row. I have to keep fighting for the kids. They deserve to have a mother. I cannot sleep until I have some justice,” she told the JC.
In August, Ms Alexander said she felt as if she had been “convicted of a crime” after Dr Schlesinger won custody of four-year-olds Samuel and Benji.
On Wednesday she was informed that her appeal against that decision had been unsuccessful.
“They just rejected everything. We submitted 60 pages of documents. I appealed for full custody or at least an increase in my visitation rights,” she said.
Ms Alexander is currently only allowed to see her children every Tuesday for six hours and on every other Sunday.
Thousands of supporters of Ms Alexander have backed her campaign, signing petitions and holding rallies in Britain.