Verb 'tensory' experiences

OK, so I'm writing my book in the first-person, as instructed in the guidebook. Suddenly, I come to the realization that maybe the verb-tense that I've chosen doesn't flow quite right. And I'm on CHAPTER 11!!!

I've been writing in first-person, present-tense, which goes something like this:
"I walk into the room and pick up the book. Opening the book, I quickly turn to page 10 and begin to read."

When all along, I probably should have been writing like this:
"I walked into the room and picked up the book. Opening the book, I quickly turned to page 10 and began to read."

Which version feels better to you, I ask? Well, I checked two of my favorite books, "My Side of the Mountain" and the "Twilight" series, and discovered these authors work with the second method.

So, in the middle of Chapter 11, I'll be making the switch on verb tenses, and will see how it feels to me.