Jon Hamm says being single "sucks".

Jon Hamm

Jon Hamm

The 46-year-old actor split from actress Jennifer Westfeldt, his girlfriend of 18 years, nearly two years ago and admitted being on his own after all that time is not enjoyable.

He told InStyle magazine: "It's hard. It's hard to be single after being together for a long time. It's really hard. It sucks."

'Mad Men' star Jon also called himself a narcissist but insisted he is a good partner.

He said: "I may be a narcissist in the way that most actors are, but I think it's not to the detriment of those in my life. I try to be a good friend, a good partner, and all that stuff.

"I'm not perfect, and it hurts when you hurt other people. But the hope is to find the right balance so you can care about your own stuff enough to live your life and do your job well while also not being a monster."

Jon opened up about his troubled childhood in the interview, admitting he is lucky with how his life turned out after a tough start.

He said: "I'm certainly damaged - there's no denying it.

"If you look at the history of my life, it's not great. When your mom dies when you're nine, and your dad dies when you're 20, and then you live on couches in other people's basements ... I mean, there's certainly a version of that person who does not come out of it as successfully as I have."

And the actor - who spent time in rehab in 2015 - also encouraged those who need treatment to seek help.

He said: "Medical attention is medical attention whether it's for your elbow or for your teeth or for your brain, and it's important.

"We live in a world where to admit anything negative about yourself is seen as a weakness, when it's actually a strength. It's not a weak move to say, 'I need help.' In the long run it's way better, because you have to fix it."