HinEmily, welcome to SR. I am a Canadian, so am not familiar with US rehab centres.
I did go to a dual diagnostic treatment centre, in house several years back, for 16/weeks.
I can honestly say it was one of my better decisions and I look fondly back on my memories of that time.
The important thing to do, is to stay focused on your sobriety.
Don't get overly involved in the social aspect. Remember everyone there is sick, too. You want to hang out with the winners in recovery!
Work hard on your programming and do journal. You will need to reread it when your AV (addictive voice)/rears its ugly head.
Best wishes on your journey to sobriety