coworker makes it his days mission to annoy me into a migraine?!?!?!

Sarah • Working mom
And he actually told me that! He has super powers to overcome the exedrine I had already taken! All he does is talk about science, video games, strategy games and his girlfriend who I am not entirely sure is actually his girlfriend or just a bunch of pictures he stole off the internet and photoshopped himself into.
He literally says 7-9 times a day "my girlfriend is cute" randomly.
Apparently there is no such thing as harassment by over chattyness. But I can't really escape or act busy because we are still in training and have the same breaks. I've gotten to the point where I hide in the women's bathroom just to get a moment of peace.
I've asked him to leave me alone in all forms of the term but he refuses to. I've tried ignoring. Idk what else to do! Help!