It's awesome when someone expresses love and devotion. That's normal. However, I understand why you're concerned. My dad is the type of person you want to avoid, lol. He's very into his girlfriend and he is a wonderful gentlement (opens the door, buys her things, takes her out, and tells her how much he loves her, etc). Yet, his love has become pretty unhealthy and toxix. He's so love struck that he drops everything (from his bills to even his own daughters/grandson) to be with her. While he definitely loves her, that same love has become toxic enough to produce jealously, clingy-ness, obsession, and other negative emotions. For ex: whenever she has to work late he automatically gets upset and accuses her of cheating on him. It got so bad one week, he tried to commit suicide when she told him she had late-night audit duties.
So... yeah. You don't want that type of 'love' in your life. Make it clear to your GF that you love her and appreciate the amount of care she has for you. However, you might want to encourage her to take up hobbies or hang out with her girlfriends whenever you aren't available. Encourage her to be in charge of her own life as opposed to you being the whole center of it. Otherwise, you WILL feel suffocated. Additionally, while things might be cool and dandy right now, when you find that you gotta go outta town for work or can't chat with her today, you'll quickly see how things turn from pretty and nice to ugly and horrible.