I actually joined the Atheist Republic in hopes of finding a group like this. I didn't find one easily if it already exists so I figured I would start this one!
Religious Trauma Syndrome is, in short, the emotional and psychological damage that is done by indoctrinating children into religious beliefs before (and/or after, but primarily before) the child's cognitive processes develop to the point that they can begin to make conscious decisions on what they process as valid information; and the very real effects that that damage can and does have on peoples lives, especially after they escape their religion. (Forgive me if this is not exact I am not a doctor and if I miss anything please be encouraged to point it out!)
Basically all of the horrible fictional consequences of disobedience/disbelief/etc get absorbed into the child's developing mind as fact; without any judgement on whether that idea makes any sense, seems reasonable, etc. and gets buried deep in the psyche of the person. This can cause panic attacks, illogical feelings of guilt (often out of nowhere and for no reason at all), and crippling self-doubt, among others. Like any trauma this needs to be dealt with in stages and preferably with support (I will try to answer any posts on here to the best of my limited ability and at the very least listen to what others need to say and converse with them) from people with similar viewpoints and experiences. I found a very good homemade short video from a psychologist who has dedicated herself to helping people struggling with this trauma, sorry for the poor sound quality! I'll link it at the bottom of this topic for people to watch if they wish, you can follow the related video feeds to get more info on Youtube as well.
I recently became an Atheist, a direction my reasoning mind was taking me for a long time; but it took a LONG time! When I first left Fundamentalist Christianity I couldn't even really leave it, not in my ingrained thought processes and self worth judgments. I spent about 8 years being Agnostic (the "I believe in something but don't know what" kind), and then non-practicing Wiccan (my involvement in that was basically being unable to lose the belief there was something spiritual going on and liking the Wiccan Reed) During those years i was constantly battling internal flashes of guilt, creepy fears surfacing of "maybe I'm wrong and I'm going to Hell..."
It was awful. I honestly dealt with that right up until recently. I really started getting back into science which i have always loved deeply. I think it was all the right-wing attacks on science i saw in the States that finally got me motivated to catch up a bit on what these "Atheists" were about. I had my interest caught immediately, this actually made sense! I studied more, heard different positions and opinions and then I just felt the difference that i felt a long time ago when i quit a bad alcohol addiction: you feel that pressure in you ease and you can tell you can finally let something go. (this isn't some "magic feeling or some crap lol it's a real thing in psychology, when you experience a release of pressure emotionally (lessening anxiety/fear/etc) when you get past an emotional tipping point in fighting addictions or recovering from abuse. Thankfully I was well aware that this was only part of the process of healing from a trauma and i started looking for support and resources online as i lost my two closest friends which shocked me, the word "Atheist" was enough to end 7 years of friendship apparently. I found this video and came to this site and forum to try and share and heal with other atheists who need to heal a bit and deprogram themselves so they can start having a normal life.
Anyways I have a busy week ahead at work but i will try and keep an eye on this thread and respond/converse with anyone who's interested, remember, you can heal up from this, there is no reason it has to scar you for the rest of your life! You are a PERSON, an evolved sentient being who is LITERALLY made of the same stuff as the stars in our universe, and you are worth the effort of dealing with past scars, not dwelling on them, healing yourself with others support and getting into REAL life!

This is a link to her website bookmarked to the text layout of basic recovery overview: http://www.marlenewinell.net/steps-recovering-harmful-relig Her website has other resources as well

The video links are from retreats she has done and i will leave them here since i know some people prefer videos lol
Video link (again apologies for the sound quality): https://www.youtube.com/watch?v=JibHYkd15h0