I would normally advise speaking to a doctor about serious concerns like this,but it is such a taboo subject,also I can understand it wouldn't be easy to talk about this subject either.
But anyway my 2 pence..I think you are maybe worrying too much.I think it is more of your ocd and your not a paedophile,otherwise you wouldn't be stressing yourself so much about it I don't think.
And another thing is,if you said you were sexually attracted to girls who hadn't started puberty yet then yeah It would be something to worry about.But a lot of guys seem to find girls in there young teens attractive,just look at how many builders will whistle at a school girl who walks by

Some girls at 13/14 are also already looking older than they are,just look at how many get into pubs.You obviously know they are off limits otherwise you wouldn't be fretting about it,and even if it was legal like in some other countries ask yourself would you then want to date girls that young,I think the answer will be no.
I think your just male at the end of the day some young girls can be pretty in there own way,It's not like your trying to date these girls or befriend them online,and I presume your also attracted to older girls and girls your age?

So yeah I think your ocd is the issue here,and the facial twitch is just a reaction you get because your worrying too much about it.