Hello Maglincer and welcome to Beyond Blue forums
Pleased you've found your way to our community of caring, friendly, supportive and non judgmental people.
I'm not a health professional, nor do I have experience with either Centrelink or NDIS. However, being an employee of various governments throughout Oz for a very long time, my thoughts are it's best to tell the truth. Have you been going to the same doctor for these conditions for awhile now? I'd think this should help.
I'd imagine that living with those disorders - GAD, tourettes, major depression, OCD and undiagnosed misophonia would make functioning in a work environment challenging. So there would be no difficulties at all in filling out the forms.
Who do you have to talk and to help you through the process? For example a close family member or trusted friend?
Keep reaching out to us Maglincer, if and when you want to. You're not alone.