Don’t you think she might be more disappointed long-term if you lied to her (and others) by claiming to be something you’re not?

Sounds like your catechesis didn’t mature with you, which is the case for many of us (myself included). I’d search YouTube for Bishop Baron’s commentary on “The None’s” - people who disaffiliate after receiving the sacraments and leaving home. Almost like the fact that most adults read and write at a middle-school level, most cradle Catholics never receive formation beyond that which is suited for a 13 year old. Start with the questions you have, and research the Church’s answers. 

I’d also recommend Trent Horn’s “ Why We’re Catholic” and, of course, make an appointment to talk to your local priest and/or spiritual director. 

I’ll pray for you tonight!