Even though you may not like the decision, it will benefit you more than you realise.
When you can't stop thinking about the same problem, over and over again, and you keep thinking about the past, you are ruminating; you're engaging in an inefficient mental exercise. Let these negative thoughts pass. Instead, focus on what you can do now. Live in the moment, not in your mind.
Some meetings have far too many participants to be productive, and other meetings have far too few participants to generate enough great ideas. You'll need to find the perfect balance between the two if you want to get the job done.