"I can't quit because I can't find another job and no one will help me with that."

Despite the economy, I encourage you not to assume that you can't find another job. You may be right, but how will you know if you don't try? And try hard.

I suggest that you not quit, but keep looking for another job. Given that you're not getting hours at your current job, this at least gives you time to look for another job.

I notice you say "and no one will help with that." It sounds like you're expecting that someone else will help you find a job. It is true that talking to people you know ("do you know if there any openings where you work?") can be very helpful. And meeting new people can help, too. But don't assume that you need someone else to "help" to get a job.

Apply for anything and everything. If your area is retail stock, go to a big shopping center and walk into each and every store and ask for a job application. Even if they don't have a current opening, fill out an application if they will give you one. If the manager is there, make sure to thank the manager for considering you.

I appreciate that it can be frustrating and tiring to fill out dozens of applications that don't turn up anything. But your odds of landing something are going to improve the more applications you submit.

None of this is to say that you should avoid talking to PetSmart HR. While it's likely true that your manager isn't required to give you hours, if there is a disparity between what you're receiving and what others are receiving, they're going to want to know why. At the very least, this will force your manager to explain.

But, no matter what happens, it's worth your time to look elsewhere. And, again, while networking with other people is always a great way to get "in," you don't absolutely need other people to help you get a job.

Above all, do not get discouraged. You're in a dire situation, but working to solve the problem (by applying for as many jobs as you possibly can) is a good way to fight the feeling of helplessness. In other words, even if no one helps you, at least you are working to help yourself.