Shoplifting at Kohls, Around $150, Went to Jail, 17 Y/O

My question involves criminal law for the state of: Texas.

I really need help. On January of 2011, I was caught shoplifting at Kohls and it was a value of around $150. I had to sign a paper that said I would never enter a Kohls store again, they took my information, and then they called the police and I was taken to jail. I was in a holding room for about 9 hours, and then they transported me to the county jail, where I spent about 10 hours. My mom posted bail (about $2000, I think) and then I was released. A week later, I got a letter from Kohls saying that I had to pay $400 so that they wouldn't charge me with another offense. We paid them and that was that, but now my court hearing is next week, and I don't know what to do. I'm 17 years old, I was illegal when they caught me, and now I have an alien number. I have three major questions:

1. What are the chances that I will go to jail? And for how long?
2. Will I get deported even if I have an alien number?
3. If I just get off with probation or a fine, will this affect my chances of becoming a citizen or getting scholarships and going to college?

I don't have anything on my record. I'm a good student, I've never gotten in trouble. I don't know why I did what I did and I feel horrible about it. And now I'm really scared, I don't want to go to jail for at least three months and ruin my whole life. Please help me.

Also, I have a lawyer, but he's not doing anything about my case. He avoids my calls, his secretaries always say he's busy, and he didn't show for my brother's child support hearing, so I don't know what I should do here. I don't want him to not show and then pay for it by going to jail.

I'm pleading guilty. Just please tell me how to act at court, what I should say, and how I can avoid going to jail.

Thank you.

1. Slim. Plan on hefty fines, probation, community service and shoplifting classes. All will be reasonably expensive.
2. Probably not, but we can't predict the future.
3. It will become part of your criminal record. If anyone were to pull said record, they would see it. Basically, this means that you will be explaining this away the rest of your life unless you get an attorney to help you.

Why does everyone want to tell us what a good student they are? That makes no difference.

DO NOT PLEAD ANYTHING WITHOUT YOUR ATTORNEY TELLING YOU TO DO SO. A common plea here would actually be "not guilty".