Don't underestimate the value of slow and steady in the world of corporate development. Many fresh out of college might seem like super stars developers that know all the latest buzz word technologies, I know this is a massive generalisation, but they don't like to work on "boring" or "legacy" and often quick to jump ship to the next opportunity.
Also, please be aware that this feeling is a common symptom of imposter syndrome.
I've stagnated at jobs in the past. I've thought it was my problem. Then I moved on to better places, where coworkers helped each other to excel, where people placed a premium on improvement and education.
If your company shoves everyone into a cubicle and assigns them individual tasks, how are you ever going to learn? If you can get a job somewhere that embraces pair programming, you might find a whole different world. You can be mentored by your coworkers and collectively solve problems, instead of feeling like you need to put your head down and produce something on your own that may be beyond your expertise.
Fresh grads, especially grads out of code schools, often arrive with a lot of buzzwords ready to go, and a script of practices they've been told are the right way, but that's all flash and no substance. It can lead to overconfidence. There's something to be said for it, though; you can fake it until you make it. The important part is that you actually make it in the end, and to do that, you need mentoring. It sounds like you're not getting the mentoring.
I know it's hard to quit a well-paid job and take a chance, but I think that's better than going to work every day hoping you won't get fired, and not growing as an individual.