How can I get an Honorable Discharge with an Article 112a pending?

Best thing you can do is to consult with a TDS JAG or hire a civilian lawyer with substantial experience in military law (i.e. a former judge advocate). First, CID doesn't "charge" soldiers, they simply investigate alleged crimes. The charges or Article 15 offer will come from your commander. When you were called in to talk to CID, you were read your Article 31(b) rights. Obviously, when you were told you had a right to a lawyer and to have the lawyer present during questioning, you waived that right. That was likely your first mistake. You were also told that you had a right to remain silent. You obviously waived that right, as well. This was likely your second mistake. So, now the evidence against you is that you came up positive for THC in a urinalysis and you may have used marijuana while you were drunk at your friends house....voluntary intoxication, by the way, is not a defense. The likely next step is for your commander to offer you disposition under Article 15 (nonjudicial punishment). If you accept Article 15 disposition, you will likely be found to have violated Article 112a and, in today's Army, this will be followed by involuntary discharge proceedings under AR 635-200, chapter 14 (i.e. a "chapter"). If you want to stay in the Army, or at least want the honorable discharge, you should discuss your goals in detail with your attorney. You do not have to accept Article 15 disposition. You can elect trial by court-martial. The advantage is that a court-martial is a criminal trial and, as such, you get a military jury, or, at your election, an impartial military judge to hear the evidence and adjudicate your guilt. An Article 15 is before your commander. So, the commander will be accuser, judge, jury and punishment authority. There is no requirement for the commander to be impartial. On the down side, a court-martial carries with it criminal penalties to include jail time and possibly a punitive discharge. You should discuss your options in light of the evidence in your case with your attorney before deciding which is the best course of action for you. You should also be aware that if discharge proceedings commence, you have due process rights. If you have been in active service for more than six years, you have a right to a hearing before a board of officers. If less than six years, you have a right to a hearing if your commander recommends an other than honorable discharge to the separation authority, otherwise you have a right to submit matters for consideration by the separation authority. It is generally unwise to waive these important rights without first consulting an attorney. Finally, please do not buy in to the urban myth that negative discharges are automatically upgraded after six months. This is just not so. In fact, negative service characterizations are difficult to upgrade, especially where the service member waives his due process rights.

I hope you read Attorney Kelly's post in detail because he went out of his way to lay out your best options to take advantage of the slim chance you have to remain in the Army. In my view you've already made five major mistakes (worrying about wife and kid AFTER the fact, blackout drunk, MJ use, waiving attorney, waiving right to remain silent). Failing to follow his advice would be mistakes six (not speaking with attorney), seven (not discussing whether to accept Art. 15 or a Court Martial, eight (waiving rights to a processing board) and nine (believing you can upgrade an OTH). As a practical matter, if it were me, I would be working closely with the Command Senior Enlisted and letting him/her know exactly what your plans are for an Army future. I wish you the best of luck.