Your therapist will not think you’re “dumb.” Many, many people do their therapy in chapters. They take care of an issue or two, then take time out from therapy to settle into new ways of thinking or a new routine. When that’s comfortable, they then go back into therapy to tackle another issue.
It looks to me like you made excellent use of your initial episode of treatment and now you’re ready for more. You’ve already discovered what a relief it is to be less frustrated and less irritable. Why shouldn’t you also want to be less troubled by whatever it is that overwhelms you?
Your therapist already knows you well. Take advantage of that. Set new goals and go for another chapter of the work.
I wish you well.