All juvenile records, whether they are shredded or not, are sealed and beyond any access other than law enforcement and the juvenile justice system. You do not have a "record" of any kind on account of a juvenile matter, and no employer may inquire into any juvenile offense. An informal adjustment (which is what you described) means the case never even made it to the adjudicatory level (trial before a judge). You are innocent until proven guilty--therefore, you remain completely innocent of the juvenile offense. You should never acknowledge or admit that such on offense was even charged or alleged against you, as the law protects and prohibits any such matter from disclosure. A juvenile offense is not even classified as a "crime" but as a "delinquent act", for which you are not found guilty, but "involved." Your matter never even reached that determination, but even if it did, there would be no record and you would not disclose the matter on any application.
If you received an informal adjustment you never went through the juvenile court process and were never adjudicated delinquent. If the juvenile records were shredded then they were destroyed, You can say with all honesty you were never adjudicated delinquent and can stop worrying about this.
Mr. Oakley has given you an excellent answer. You state that you have a significant anxiety order. Take a cab or have someone drive you to a Maryland State Police office where, for a small processing fee, you can obtain a copy of your official Maryland Criminal record. Simply tell the officer who processes you that you need the record for employment purposes. Many people need to obtain this document for employment purposes so you would not be making an unusual request. Do not tell him anything about your juvenile misadventure. He will take your fingerprints and process your request. You will then have a copy of your record, assuring you that you do not have a criminal record. Although your anxiety may present you with a challenge in obtaining the record, once you have the record you can obtain reassurance that your juvenile matter will not present you with problems in the future.
This is not legal advice it is general information intended to guide you to speak directly with a lawyer who is licensed to practice law in Maryland.