I agree with you that this "practice weekend" is a good thing. It will give you both a chance to absorb how it was being together again. I know exactly what you mean about not even knowing if that trust will ever return. I couldn't imagine not knowing what was going on and it went on for 8 years, I give you do much credit for staying as strong as you have and for staying with him. I've been with my fiance for 3 years and I knew he had a problem, I just didn't know the severity of it till about a year and half into our relationship.
Like you, I could hear a big change in my fiances voice. He sounded very committed and serious about his recovery and so far that has held up. He still has that mentality and motivation. Things have been good cause he's staying sober but believe me, I have had my moments and so has he but we talk through it and it's working. Don't feel like you're crazy for feeling the extremes of emotions that you are feeling, it's completely understandable. Once he's home for good, it's going to be so overwhelming but it will get easier as long as he stays on the right path and you stay on the right path by remembering to take care of yourself and your children.