Sophie Turner thinks Joe Jonas "saved [her] life"

She recalled: "I was going through this phase of being very mentally unwell.

"He was, like, 'I can't be with you until you love yourself, I can't see you love me more than you love yourself.'

"That was something, him doing that. I think he kind of saved my life, in a way."

But things haven't always been smooth for the couple and they even split up for a day - but quickly reconciled.

She told the Sunday Times magazine: "It was the worst day of our lives. For a second we both had cold feet, then 24 hours later we were both, like, 'Never mind.' "

Growing up in the spotlight caused Sophie, 23, major problems with her body image, and at one point she would eat nothing but nuts but she eventually sought therapy when her weight dropped so much, her periods stopped.

She said: "Suddenly, everyone's metabolism slows down at 17, 18 and then that's documented. My skin and everything. People commenting on it. I was too aware of my body at a young age. And it just kind of took over my mind, it was all I would think about. Calorie counting, everything. Oh, I'll just eat nuts today.

"I stopped having my period for a year -- that's when I decided to have therapy."

The 'X-Men: Dark Phoenix' star now refuses to do scenes in a bikini or underwear because of the "agony" it caused her and she won't accept roles that require her to lose weight.

She said: "I've learnt that I have to turn down jobs if I need to lose weight for them, because it's not good for my mental health at all.

"You feel so much pressure to say yes, but I've learnt that I have to put my mental health first, beyond anything, otherwise I'm screwed and then I might actually end up in rehab."