The 'Man of Steel' star and 'The Big Bang Theory' beauty split up last month following a brief romance and friends of Kaley say she found the interest in their relationship difficult to deal with.
A source told the US edition of OK! Magazine: ''She just got overwhelmed with the very public Superman relationship. She's not used to that much attention and chaos in her life.''
Henry had split from actress Gina Carano earlier this year following a 10-month relationship, while Kaley briefly dated musician Bret Bollinger after ending her engagement to Josh Resnik in March 2012.
Kaley also previously dated her 'Big Bang Theory' co-star and on/off on-screen boyfriend Johnny Galecki for two years, but the pair managed to keep their relationship a secret for the duration.
She has now moved on to tennis player Ryan Sweeting and is much happier with this low-key romance.
The insider added: ''She thinks Ryan's a really hot, nice guy. It's nice that he's not really an industry guy.''
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