Thanks for bringing your question to JustAnswer.
No, this is not a trivial question!
Being in a healthy relationship involves being able to trust one another. You don't have that.
A healthy relationship makes you feel like your "best self"...it doesn't sound like you have that either.
I always find it interesting to note what information people chose to put in their short descriptions of their situation....and you wrote that your family hates her, and you've hidden the relationship. Do you want to go through life with tension with your family? Unless there is some history with them to contradict this, most families want to see their children happy...and they see something in this girl that makes them fear for your happiness.
When we're first in love, and the physical attraction is strong, sometimes we get swept away in the romance of it all....without doing "due diligence" in checking our partner's character.
Tying your life to someone who cheats, and who your family hates is not the recipe for a happy life. Knowing and understanding you is great---but if she knows and understands you so well, why did she cheat-- she had to know how much it would hurt you. Anyone would feel hurt at that.
I believe you made the right decision to leave. Try to ignore the drama of the tears. She didn't seem to mind hurting you by cheating...and this is the natural consequence of her actions.
Once you are a few weeks away from this situation, I believe you will look back with relief, not regret.
If this has been helpful, please click ACCEPT.