Ok, bro, here’s my $0.02! I’m actually entering the seminary in the fall - I’ve already been accepted since last spring, but I’m finishing my bachelor’s degree before entering (I’m 21).
I’m going to say that it is great what you’re doing. Keep going to Mass and Benediction! Keep reading about the Church and spirituality! Those things are great, and essential for your discernment. I don’t think you’re wasting your childhood - after all, the only waste of a life would be not to become a saint! And you’re trying to get close to God, which is what matters.
I will say, though, that a little interaction with the secular world won’t hurt you. There’s nothing wrong with texting, with music, with going on trips, or movies, or anything like that. I’m studying at a secular university and none of my friends practice their respective religions, but we’re able to get along quite well. They respect me and my faith, and I respect them; we do all kinds of great stuff together, everything that regular American college-age people do together. Occasionally my faith will get in the way of a particular activity or conversation that wouldn’t be good, but I wouldn’t trade my friends for anything. I wouldn’t trade any of the things we do for anything in the world.
One thing we have to remember is that all people are sinners, ourselves included. Yes, we are called to be saints; but the lost sheep Jesus spoke of in the Gospels are in the secular world, among our friends, our classmates, our co-workers, even in our families. If we refuse to hang out with them because their activities are too “secular,” we lose not only wondeful relationships but also chances to bring our brothers and sisters to Christ.
I read Bl. John Paul the Great’s biography by George Weigel (this is required reading for you, btw, future priest!

), and one thing he mentioned is that the newly-ordained Fr. Wojtyla learned as much as he could about the culture of the young people he was ministering to, so he could be more accessible to them. For us, that would mean knowing about pop stars, movies, rock bands, the newest fad technology, etc. It also means enjoying some things about popular culture that can be fun for us in our youth years. I’m really looking forward to the Grammys tomorrow night - two of my favorite bands, The Black Keys and Mumford & Sons, are nominated for a whole load of awards! And I’ll be texting with my buddies the whole time, following the show.
No one’s saying you have to do any of this, or immerse yourself in a culture you find distasteful. But it wouldn’t hurt to be involved a little bit, especially if you’re retaining your love of Jesus. In my case, it has brought me friendships that I wouldn’t have had if I just spent all my time at the church or in the school library. I love my friends, and a number of them have told me that just seeing me as a normal guy, seeing a future priest as just one of them, has changed their ideas about Christians and the Church.
Here’s an example. My buddy is an agnostic/atheist - some of sort of secularist who detests Christianity and the teachings of the Church. However, he and I became pretty close. We do all kinds of stuff together: we like the same bands, we see films together, we even brew our own beer in his living room! Great guy. But we also have our religious discussions, and he told me that because of me and another Christian friend, he realized that Christians aren’t the fools he thought we all were for holding “illogical” beliefs. So there you go.
Hope this helps! I know it’s long, but I thought some examples would help you.