I think everyone gets hit with this feeling at one point or another in their guitar playing lives, usually the first time they see someone who totally blows them away and learns that they've started when they were 8 and played 6 hours a day or something crazy like that. I know I was depressed when I had to face the reality that I wasn't going to be getting into major bands when I was 17 and releasing records like Steve Vai. I had to say to myself, "look, you can't help the fact that you started playing 10 years after Steve. All you can do is try your hardest to progess". So I stopped trying to be Steve Vai and started trying to find my own, unique sound (which is what I'm still doing!). Try and find your niche