JPA MySQL exponentially slower - mysql

Question

I have a problem when switching pages on my webapp.
When I switch between pages (Making requests against my DB), the response time becomes exponentially slower. See for example output from chrome, where I switch between two pages repeatedly:
Chrome screendump
But it is session specific. If I open another window/browser, the problem isn't there (though still in the other session), until I start switiching pages again.
When the page loads, this is called:
ActualTestGrabber actualTestGrabber = new ActualTestGrabber();
concretetest = actualTestGrabber.getById(80);
And for the "grabber":
public Concretetest getById(int tf){
EntityManager manager = getManager();
TypedQuery<Concretetest> query = manager.createQuery("SELECT w FROM Concretetest w WHERE w.id=" +tf ,Concretetest.class);
Concretetest result = query.getSingleResult();
Close();
return result;
}
And the getManager and close:
#Transactional
public EntityManager getManager(){
emfactory = Persistence.createEntityManagerFactory( "DSLTestV4" );
entitymanager = emfactory.
createEntityManager( );
entitymanager.getTransaction( ).begin( );
return entitymanager;
}
#Transactional
public void Close(){
entitymanager.getTransaction().commit();
entitymanager.close();
emfactory.close();
}
Am I doing something wrong? Why does the querytime get exponentially worse?
Really hope someone can help.
EDIT:
SQL Code for Concretetest
Best regards
Benjamin