Many people who leave religion report feeling isolated: they've left their church community, suffered strained relationships with their friends and family, and often live in a place where it is hard to meet like-minded people. It can be reassuring and healing for these people to express themselves and know that they are not alone.

Reddit provides a number of wonderful ex-religious communities. They have forums specifically for people recovering from:
Jehovah's Witness

There is also a sub-reddit dedicated to collecting deconversion stories, much like
thegreatproject is a well-established resource with many articles and a very active forum.

Recovering from Religion is a non-profit that offers  resources such as live chat, phone support, and local therapy connections for those going through religious trauma.

If you know of another site that should be added to this list, please send me an email.