Sugar Land . . . you've got a problem.
But first: You don't say how long ago the plea was. Or what you were chaged with, or whether the attorney was retained or appointed, or whether it is a misd or a fel charge, or if you have priors, and if so what those were. All of these factors bear on what your answer will be.
Second: The plea was made in open court. You were asked "are you pleading guilty because you are guilty and for no other reason?" And you answered "Yes". That is called a judicial admission (of guilt). Hard to come back from. You are above the age of criminal majority.
Third: IF YOUR ATTORNEY KNEW of the exculpatory information and withheld it from you, you have a shot at getting the plea withdrawn. IF THE STATE KNEW of the exculpatory information, and contrary to law (Brady v. Maryland, inter alia) witheld it anyway, ANY YOU CAN PROVE IT, you have a pretty good shot at withdrawing your plea or (and this is probably your best remedy anyway HIRE ANOTHER ATTORNEY, and file a Writ of Habeas Corpus alleging Ineffective Assistance of Counsel and Failure of the State to comply with their duty to turn over to you and your counsel all excuplatory information in their actual and constructive possession.
Fourth, if your attorney was coercing a plea from you, Boy Howdy do you need a new attorney.
If you successfully complete DADJ/DD:
a) a conviction will not appear on your criminal record.
b) you will, after a time, be able to file a Petition to Limit the Distribution of Criminal Information to limit the number of entities who can see the facts surrounding this charge, and to some extent, its existence. This is not an expunction, which would wipe the slate clean. You are ineligible for that since community supervision is involved in the disposition of the matter.
This answer is in the nature of general information only and does not constitute legal advice or the formation of an attorney-client relationship.