Hey bro,
I'm sorry to hear live is going to roughly for you now.
I'm going to give my advice, although I've never been in your situation, I did battle a minor bout of depression in college when nothing seemed to be going right.
First off, the faith based addiction programs or going to church is an ok option, but not one I'd suggest right out of the gate. When you feel like you are no longer in control of your own life and actions, you can then turn to "faith" and put your life in the hands of invisible being.
Until then, lets stay grounded in the rational world and focus in on what is working for you. You mention that you have a great job, home, and cars. That is good. Focus on work, devise some near term and attainable goals regarding your job, or possibly some home improvement, that you can use to get your mind in the right place. Start small, little wins have a HUGE i mpact at this point because it sounds like nothing is bringing you pleasure.
Oh, and just because I am not a fan of the faith based or church based remedies, does not mean I do not think you shouldn't continue your treatment for Opiate addiction. That is a good news bad news situation. The bad news is that you will be in recovery for life, the good news is that recovered addicts can live fun and fullfilled lives, which i am sure you will be doing yourself sooner rather than later.
So continue your treatment. I am not a fan of methadone treatment, its substituting one drug for another, but its also a start. Stay dilligent with getting treatment from addiction specialists and medical professionals. Have you considered a short term inpatient option? That could give you a much needed break from your life now and help ween you from the methadone.
The DUIs are something you need to get under control. It sounds like this 3rd one isn't serious, and I hope your blood work comes back clean, but in the future be more careful when it comes to that shit. Stock sodas in your garage. If you HAVE to go somewhere and you know you wouldn't pass a blood test, CALL A CAB, or call someone you know. Sounds lame, but its a hell of a lot better than a DUI.
I'm sorry to hear about your mom man, that really sucks. If its really getting to you, you can also see a couselor that specializes in the grieving process. My aunt did that when my grandma died and it helped her a lot. They put things in perspective and explain why you are feeling certain things and what to expect throughout the process.
Lastly, forget the haters on here. For better or worse this place attracts a wide range of people and personality types, many of them revel in other people's misfortune and misery, just like in real life. You just have to ignore them. Realize that those who poke fun at your misery, or try to trivialize it, are probably struggling with things internally that are much more difficult to deal with then your issues. That type of behavior comes from the darkest reaches of your emotional brain.
So to sum it up, find something, anything, no matter how trivial or small that you enjoy. Maybe its a cup of coffee in the morning, a TV show once a week, exercise, talking to a friend or family member, anything, find something you enjoy and focus on it and try to put some enery into it.
Continue your treatment for addition and consider all available options.
Force yourself to smile at least once today bro.