What should I do?

So, I'm 17 and I have been with my girlfriend for over 2 years, and have known for 3. However, recently, I have been really attracted to one of my other friends, who I've known for almost 2 years.Things between me and my girlfriend just seem a little... unexciting recently. It could just be we haven't gotten the chance to date in a while since we're both broke, but even talking to her seems a little... like, normally we don't really have much to talk about. We already know everything about each other, and occasionally there's something to talk about. We're really just saying "I love you" over and over again, and there's no conversation. But this other friend, I've been texting and talking to now and it just seems more interesting. It's fun to tell a bit about yourself and learn about someone else. But I still love my girlfriend, and I don't want to hurt her. But should I continue being with her, if I might have feelings for someone else? There's no reason I shouldn't be with my current girlfriend, she's a great person. These new feelings just... came up. So my problem is, how do I deal with these feelings for my other friend? I have really only dated two people, both for longer than a year. These new feelings, however, make me wonder. Do I need more experience before I decide who to be with? Should I talk to her about it? Should I keep it to myself and learn to get over with it? One side of me says to not hurt her and just deal with it, and the other says I'm too young to pick who I want to be with for the rest of my life and need more experience. I really don't know what to do, and I could really use some friendly advice. Thanks for taking the time to read this.