It's great to have people who's work you look up to. It provides inspiration, and motivation to improve your own work. It can be a problem though when you start comparing your own work to somebody who has had more experience than you. You can start to feel like maybe your work is inferior, or even just horrible.
Discouragement isn't going to help you get better. When you start your work will not be very good, but that's the point. That's how we learn and improve the quality what we produce. You're probably not going to be as good as someone who has had more experience than you, but remember that at one time they were in your shoes. If you can, go back and look at some of their older work.
Unless somehow they're the perfect epitome of graphic design (which I guarantee you they are not), they also have someone they look up to. Someone who is even better, who in turn looks up to someone else, and so on. Admiring someone else's work, and setting their level of quality as a goal will help you get better.
The fact is, as long as you stick with it and work hard, you'll always be getting better. Will you ever be "perfect"? No. And neither will your hero. Neither would the hypothetical "perfect" designer. No matter who you are and how much experience you have there will always be room to learn and improve.
It's easy to fall into the trap of comparing your work to what the people you look up to have done. Believe me, I fall into this trap all the time. I wish there was an easy, magical fix that I could share with you, but there isn't one. Much like learning design itself, it takes a lot of discipline and practice to step back and look objectively at your own work.
One thing I have found that helps put one's abilities into perspective is to share work. I don't care how bad you think it is, share it with somebody who's opinion you trust. They will always point out things you could improve, but they will also find some positives that you couldn't see.