No thousands and thousands of butterflies turning one´s stomach round and round in English when one is in love?  

Yes! - but a different meaning altogether.  Butterflies in your stomach can mean anything from the feeling you get when you see the one you love to the nervousness you feel before a job interview or giving a speech.  But the dictionary definition of ´stomach-turning´ is:

turn one´s stomach

´Nauseate one, disgust one, as in That mess of spoiled food turns my stomach. This idiom alludes to being so nauseated that one vomits, that is the stomach in effect turns around and brings up food. It was first recorded in 1622.´

I can think of several times I have felt like that about people - but not people I´ve been in love with .  So if you ever fall in love with an Englishman try to remember not to tell him he turns your stomach!  

I think she means ´makes my stomach churn´

What?  The OP you mean??  ´churning´ is worse than ´turning´!  

hahaha-I think you´re right!  I thought it meant like being agitated or excited but obviously not.