Rather than give up so quickly, why don't you call your job and speak openly and honestly to the boss/supervisor. Explain to them that you are sorry for how you ended things. This job is important, as they will be used as references when you seek another position, even outside of the healthcare field. Also, you should consider going to school for an LPN or RN degree/diploma - it opens your world to various positions and atmospheres.
Let me tell you something - I am a highly sensative person; to the point of it being a downfall in my life. I understand how it feels to want something so bad, that I self-sabotage my role (being late, not calling when I should, quiting just because I feel like I want too, etc) or job. UNTIL, I learned that people love to see other people fail. They love when we aren't at our best, because if we were doing well, then they would have something to complain about in there life. So, I stepped my game up. I became a more responsible person - for myself, and because my word is my bond. All we have is our reputation, and I believe that. If you let this one bad experience change your outlook, then you will let another bad experience change another outlook. You will never be happy with anything that you do, and you will find fault - even when nothing is wrong.
So - before huffing and puffing, and thinking that you no longer want to be a CNA, consider this: There are thousands of people who would love to become a CNA right now, but can not afford to take the class. There are plenty of people who don't have the time, because they have to work multiple jobs to feed there families. The list goes on. You are a CNA now - while others are actively trying to become one. The economy is tough girl!! Put on your big girl panties, and tell the world that you are strong and regardless if you made a mistake, you will do your best to make amends and become a better person.
Sorry to have written such a long reply, but you sound like me when I was a youngin', and I wish I had someone to straighten me out back then. You are more blessed than you realize - just take a look around you.