Recently I've discovered an ex to be a sex offender, I'm in shock and in a state of mind in which I do not know how to react or deal with this kind of news.

Some advice would be great as I'd like to stop being in this kind of vicious circle

What kind of sex offender.

Urinating in public ( makes you one many places)
Having sex with a underage girl ( he was 18 she was 15 mabye)
Or did he have sex with a much older girl.

And stop what, did you and he have kids together?

Grooming children online and sex with underagers and I mean feeling sick and unable to stop thinking about the general situation

And it was 24 & 14