The Open Minds Foundation and Freedom of Mind websites are well-organised resources for all those affected by sects, cults and undue influence.
I recommend psychologist Marlene Winell’s guide Leaving the Fold: A Guide for Former Fundamentalists, and the books of Janja Lalich. For ex-JWs, Exiting the JW Cult by Bonnie Zieman contains sound advice about post-JW life.
Psychotherapist Rachel Bernstein interviews ex-members of various cultic groups on her podcast IndoctriNATION.
ICSA (International Cultic Studies Association) researches cultic groups and organises workshops and conferences. ICSA lectures and talks are posted on their YouTube channel.
For a very thorough examination of JW beliefs, I recommend Paul Grundy’s website JWfacts.com.
My paper on the Jehovah’s Witnesses can be downloaded as a pdf below. It is intended for helping practitioners, but ex-members may also find it of use. The paper is available in both English and Spanish. Please note that the Spanish version is an earlier one.
Ayudar a los ex testigos de Jehová (Spanish)
There are many pop psychology books out there, but for an evidence-based introduction to generally feeling better, I recommend the free online course taught by Laurie Santos: https://www.coursera.org/learn/the-science-of-well-being.