It's not really a big confession where therapys concerned.
If you mention it, T might advise you that is your choice as to whether to stop going or not. As therapy can't really work if you are numbing out. It's wasting your time.
Perhaps this isn't the time for therapy for you if it's having such an affect.
I'm an ex addict and T aid from the beginning, if I begun using again, to tell her. Because. It won't work like that. She didn't enter any dramatic rescue role. Therapys not about that. AA or something similar fits that role.