supporting evidence for PIP

I've just received the dreaded brown envelope saying I need to move to PIP. I've been receiving DLA for about 20 years for severe mental illness and associated physical issues. I've spent well over 7 years on psych wards in total, was on enhanced CPA, had been sectioned several times etc etc. Unfortunately our MH trust merged and became Norfolk and Suffolk Trust and, as has been well covered by local and national press, cut costs, haemorrhaged staff and is in special measures. Like a lot of former patients I was referred back to primary care and get no help. So now I'm stuck on how to get accurate supporting evidence. My ex-psychologist retired, my ex-psychiatrist left the medical profession, my social worker moved, the ward managers have either retired or moved on since they closed wards. My GP is great but I doubt he has time to complete anything other than the tick-box form they send him. I was assessed last year under the MHA and whilst I talked myself out of being sectioned I doubt the reports of the state of myself and my house weren't exactly glowing but with no contacts in the service I've no idea if a) I could locate the reports b) I'd be allowed to copy and use them.
Could I include newspaper articles to back up my argument that I'm one of many needing help and receiving none? Would pointing out that I'm still (I assume) on the Severe Mental Illness Register at the GP carry any clout?
Also, if I leave contacting the DWP to tell them that I do wish to apply until the last minute (9 Sept) will that buy me a bit more time or does the clock start running from the day they posted the letter?
I've only just completed my ESA renewal in June and I'm worrying that I've heard nothing because they weren't persuaded by my reliance on my own testimony.