Could Adderall (dextroamphetamine and racemic amphetamine) help give me the energy I need after stopping methadone?

Yes but. Adderall (dextroamphetamine and racemic amphetamine) does increase energy levels. However stopping Methadone might take several weeks before your body starts returning to normal with resolution of withdrawal fatigue. Supplementing with Adderall (dextroamphetamine and racemic amphetamine) might just replace one addictive medication with another.
Not appropriate. Adderal is specific for certain diagnoses. It is not for attempting to increase energy during drug withdrawal. You could wind up needing to be detoxed from the adderal.