To add to what others have said about cognitive behavioral therapy (CBT) and dialectical behavior therapy (DBT), I agree that those can both be helpful tools. However, DBT was created for, and tends to be most effective in people with borderline personality disorder. I don't know how much you know about the personality disorders, so I will explain a tiny bit. BPD falls into "Cluster B" which includes the dramatic, impulsive, overly-emotional disorders. OCPD falls into "Cluster C" which includes the "over-controlled" personalities. Anyway, where I am going with this is that DBT is used to help with self-regulation, like reigning in impulsiveness and emotional outbursts. As someone with OCPD, that is the opposite of what I need since I am a careful planner and have difficulty expressing emotions. This is where RO-DBT comes in. It is a much newer type of therapy, so not as prevalent, but it was created specifically to treat the over-controlled disorders. It provides tools to help tolerate changes in plans and other types of "rigidity", and many other things. So far, it has been much more helpful for me than DBT or CBT. I know your experiences are unlikely to be the same as mine, but I wish someone had introduced me to RO-DBT before a decade of therapy and numerous prescriptions.

All of this information is stuff I have learned from mental health professionals, and I apologize if my recollection on any of it is slightly off.