How can I change to be more serious?

I have been on my first professional job after undergrad. It’s my first experience in full time and doing the work I do. I’m a substance abuse counselor. The problem is I have always been goofy light hearted and not stern enough. I don’t set firmness in my tone of my personality. I had severe anxiety about doing this job and now I feel I have ruined the group atmosphere by being too light and flowy. We talk about serious thing we have serious problems going on. I feel embarrassed and sad that I ever did this. What if i ruined someone’s life? Someone’s experience? Someone’s sobriety? I’m not doing enough. I struggle with this same thing outside of work so it’s difficult. I’m trying to see this as a growing moment and experience but I’m sad and feel I may have ruined the groups therapeutic atmosphere. I suck. My personality sucks. I just feel so stupid
How can I change to be more serious?
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