Mum-of-two Nicola fell ill during a business meeting after she hadn’t heard from husband Tom Williams in two weeks.
The 32-year-old recently tweeted him, pleading: " When will you be home, Tom? Your kids need you,"
Tom did not appear to respond to Nicola’s attempts to contact him on Twitter, which reportedly left her feeling stressed.
Tom has been in Las Vegas for weeks at a time as part of his job as a concierge.
A source told a UK magazine: "She stopped eating because she had no appetite through stress. Nicola was surviving on Diet Coke and water and was barely sleeping at night.
"Then one morning it all go too much. She was in a meeting and just couldn't concentrate - her head was buzzing. As she stood up, she passed out cold."
The insider added: "He might be back in the UK, but the future of their marriage is uncertain."
NICOLA MCLEAN: 'ANOREXIA HAS LEFT ME NEEDING IVF TO CONCEIVE'
Following Nicola’s dramatic collapse, the former model’s agent told a UK newspaper: "Nicola blacked out as she stood up to leave a meeting, she was dehydrated and under a lot of stress, she hadn't been taking care of her health as she had had so much on her mind, but is now making sure she eats and tries to get some sleep.
"She's going through a very difficult time at the moment and just needs some time to try and get back to being her usual, happy go lucky self."
**You may also be interested in: SHOULD YOU WALK AWAY FROM AN UNHAPPY MARRIAGE?
**