Voices, dear one... you are NOT stupid... and anyone in your life who tells you that/thinks that of you... needs serious (re)consideration. Those who truly LOVE you would take you as you are... and not ridicule or humiliate you... or your thoughts/beliefs. They may not agree with them, but they wouldn't use them to chip away at your self-esteem so that THEY could feel "right." Love... does not look out for its OWN interests, especially not in that way.
Please... tell your girlfriend (TELL her!) that you are NOT stupid... and that you have a RIGHT to believe what you will... and ask questions to better understand... even if they/it seem "out there."
I realize that, like most folks, you probably don't want to be "alone" and so risk losing your girlfriend by telling her this. If she truly loves you, you won't lose her. But, if you allow her to believe that you're stupid... and let you KNOW she believes that... you will lose yourself. Which is WAY worse. Believe whatever you will, dear one... regardless of what anyone else thinks. And if it changes, so be it. Believe that, too. It is your human right.
Again, I bid you peace... and strength!
YOUR servant and a slave of Christ,
SA, who is a little irritated at your "girlfriend," admittedly