first timecriminal mischeif felony case

Unfortunately, being under the influence is not a defense to a criminal act in Texas. So, that argument isn't likely to gain you much traction with the DA's office. There may be other factors that could help your defense, but there's not enough information here to say whether that is true or not. Depending on your prior criminal history, if any, there may be options out there that can prevent this from becoming a final felony conviction on your record. Any attorney would need more information to tell you that definitively, though.