I see you have tried CBT - which can be really useful as a way of managing your difficulties but I don't think necessarily helps with long standing difficulties at the root.
You sound like you have reached the point where you realise you want to do something longer term and I do think that real change does take time, a lot of time, sitting with someone week by week, even several times a week (in my case!). It's a slow slow process to achieve a real shift, almost like you have to take the time to grow up and develop all over again, but this time in the presence of a thoughtful, responsive, containing (and sometimes challenging!) other person, who can truly make a space for you without thrusting themselves into that space.
If you are thinking about psychodynamic or psychoanalytic psychotherapy, then do choose someone who is on the BPC register, which is the specialist body for that type of therapy.
www.bpc.org.uk
All psychotherapists listed there have done years of training as well as years of work on themselves in their own therapy, without which you can't be registered.
The BACP register is also not a bad place to look but it includes people who may have only done counselling diplomas and limited time of their own therapy.
Many psychotherapists will charge around £50 an hour and maybe less if you are on a lower income. In addition depending on where you are you may be able to access low cost therapy with trainees who are nearing the end of their training. This is better than it sounds - trainees are closely supervised by senior clinicians and often are doing the training after a long career in eg psychiatry, clinical psychology.
The Institute of Psychoanalysis for example has a clinic in London and also a service in the North (based in Leeds) where you could maybe get low cost therapy. You could have a full psychoanalysis which is five times a week - this would be a big commitment and seem totally crazy, but it would also be life changing. You simply can't spend that amount of time with an analyst and not be changed.
www.psychoanalysis.org.uk/iopa-clinics/low-fee-scheme
You'd be surprised at what might be possible. My advice would be to just start a conversation with someone or some people. See a psychotherapist for a consultation, or phone the Institute and have a chat with them. Things might emerge that you can't yet know about.
Good luck, it sounds to me like you kind of know what you want.