Help completing PIP Review form please

Hi,

I've received my first PIP review form 1043. Can you help please?
I did keep copies of everything I sent in when I claimed PIP before thankfully!
Do I have to rewrite everything or can I just send copies of those copies and put any changes (or not) on the form? My main claim is due to MH, depression, severe anxiety & panic. I also have a really bad back which limits what I can do repeatedly but I can walk more than 200 metres even though I would be in pain. My last letter from my consultant was in December 2015 but back is a lot worse than then and when I claimed PIP last. I havn't contacted my doctor due to not being good with the telephone or going to the surgery. Should I contact GP before filling in form or just write about increased pain as it's obvious from the letter that it's degenerating problems?
Hope I've made sense, I get muddled easily I'm afraid. Thanks in advance.

Thank you for your help, I've also changed my visible name.
I am under a psychiatrist so hopefully she will write another letter although she's not the best at that!. I will phone Dr 're my back and see what happens. I avoid appointments because of my MH so havn't seen a Dr for a long time.

Well, I tried to see my doctor but I can't even get a phone call within the time frame I need so I will just fill in form as last time. I can't cope with the stress involved. Psychiatrist is writing a letter to support my claim so that's good. She was pretty angry that they were even asking me again to prove my claim - wish she was in charge of DWP!