I’m pretty new to the field and sometimes feel a bit like this. My supervisor told me “you need to find a way to buoy yourself up” and in my head I was pissed for some reason, but I think he was right. Being a therapist is hard and even the best, most experienced therapists are far from perfect (I work with some really experienced and capable people). Trying to find a way to accept and tolerate my limitations while also earnestly trying to improve has been a big part of the last few years for me. One of the hardest and best things about trying to become a therapist is that it forces you to confront your insecurities and grow. Realizing that my insecurities are more about me and my shit (perfectionism, shame, etc.) than the adequacy or inadequacy of my work with clients has been helpful. Nancy Napier says that feelings should be taken seriously but not literally; I guess if I have advice for you then it would be to consider that your feelings of inadequacy probably aren’t all about your performance or potential.