Welcome to the caring and supportive world of Beyondblue forums. I'm sorry you have not received a response as yet. Its most unusual but does happen occasionally if nobody knows quite how to help. Unfortunately I have no experience with Centrelink or DSP procedures myself, so am unable to assist with that.
But by me welcoming you now it will bump your thread back to a recent post, and I'm hoping another member may now spot it and be able to offer helpful advice.
Yes you're right ... quite the combo with your diagnosis of mental illnesses. It does sound as though you have a very supportive mental health team behind you, which is so important. I am diagnosed with PTSD and associated anxiety and depression. Its very hard living with mental illnesses, and difficult to establish or maintain trusted friendships. You did not say whether you have a supportive family and friends around you. I hope you do.
Please know that you can post here any time you would like to. The people here are very understanding, supportive and helpful. We have a lot of other members here who have your illnesses, not necessarily all of them, but certainly some. I would advise that you have a read of some of the other existing threads in the Depression section as you will find a lot of helpful information there. Feel free to reply to any of those threads as well.
I hope you will not be put off by a slow response to your post, and will post again. I'd love to hear more from you. If I dont hear further from you however, I wish you every success with your DSP application. Just be honest and upfront and try not to get too anxious about the process. I wish you well.