It was among the most challenging years of my life. Not just for me personally, but playing the role that left me suffering," she told Variety.

"It is the very first time I had started therapy. I've been open about it. It started in the middle of Season 2 because I was suffering many issues just prior to when we began shooting.

It was a nightmare. Also, I developed an irritable rash, which was all over the body and lasted for 3 months, which wouldn't let go. 

I, too I said, caught fire in my leg that lasted for 3 months. I couldn't walk at all.

Kaley Cuoco started therapy

It was truly a dark period," she said. "I did not know how to handle it. I was putting myself through work in order to hide my depression, and also how angry I was.

Kaley Cuoco

However, my character was so depressed it was not helping me! I was really really struggling. There were a lot of tears.

The trauma I went through could have helped with what I had to accomplish for this season. Did I really want this to occur? Oh my god, no. Was I planning for that to occur? No. 

It was life-like art in certain instances that it felt eerie" she said. "I really feel the suffering I went through, and a lot of it was real on film.

The scene in which I broke off with Marco -I'm not kidding, I was unable to breathe. I was in the bathroom and felt like I was going to suffer an attack of panic. 

The thing is, what happened to them has happened to us. This isn't what I'm trying to say. It was simply the idea behind the breakup and the way I said the words.