I'm a foster (soon to be adoptive!) parent through CFSA. Once you're a foster parent, there are several types of support groups within the system. There's also a separate non profit group called the Foster Parent Advocacy Center, and the Center for Adoption Support and Education, and the Post Permanency Center. The last two have support groups for adults and kids, and adoption positive and trauma-informed therapy for kids.
For us, about to adopt a 5 year old, it's been a hard road. But it's wonderful, and I wouldn't change a thing.
But - if your husband isn't on board, don't do it. It's hard, really hard on a marriage. And we are coming through it stronger on the other side, but I could easily see people falling apart over the issues that arise during the whole process.