Hi Theresa,
I had been sober for two years through AA when I had a relapse using benzos. I opted for treatment because I was a bit of a mess.
A good treatment centre dries you out if necessary, gives you 3 squares a day, you are in 'group' several times a day - give you some information about your illness/addiction/disease - and send you out into the world. From there, it's up to you to sink or swim. I would suggest many meetings.
If you're already sober, and doing IOP, I'm not sure what real benefit treatment would have. What specifically are you struggling with?