First and foremost do not despair! In the short term it will be a problem however for most entry level positions the issue will be more about how you handle the problem than what you did.
Be sure to mention the issue in your letters. Discuss how the whole thing changed your life and what you do to stay clean and sober. Further when you apply for a job, instead of offering recommendations if requested, send along recommendations that acknowledge they know about your previous issues and how you addressed those issues.
As for your plea's , you should find competent counsel and see if these plea's can be attacked collaterally and if you could get anything expunged do to your failure to be given all of the facts. If this is impossible you may want to see about getting a Governor's pardon or if it is too soon to see if your state has a statute that relieves you from the civil disabilities of a conviction. If so, apply for that at the very least. You may want to see someone who specializes in post conviction relief or appeals as they may be able to help you best. You should also try to hire the best and most experienced attorney you can find to reduce the possibilities of miscommunication again.
This answer does not, nor is it intended to, create an attorney-client relationship or constitute attorney advertising. Rather, it is offered solely for information purposes. Since the facts of each case are different, it is critical to consult with qualified counsel with whom information can be shared and assessed under an attorney-client privilege, so that competent advice can be obtained on which you can make informed decisions.
You will be hard pressed to get a job in the accounting world. Responsibility for financial information does not usually go to someone with a theft on their record.
You might want to discuss your options with a career counselor before you leave college with a degree in a field that wont hire you.
This answer is not meant to be legal advice from its provider. It does not create a client/attorney relationship and any action taken based on this answer is at your own risk.