My PIP assessment experience

Hi I’m new here.im not quite sure if this site is just for physical disability or mental illness to.
i have mental illness and oesto arthritis of my right knee.
i had a pip assessment in 2016 basically they halved what I was getting on dla but award letter said my next assessment was August 2018 but I was called for re assessment in Feb this year two weeks after that I lost pip scoring no points .
i was in a relationship but this sent me over the edge especially when my partner said as she had lost her carers allowance for me she wasn’t going to do any caring for me I was already in crisis so I finished the relationship .
so now I’m trying to cope without a carer.i told them at my assessment I need help in the kitchen and went into the reasons why .so basically I’m not eating meals now I just snack on chocolate and biscuits .i need help getting in and out the bath and my shower is over the bath to .
ive been getting washed by sitting on the loo and using the hand basin to wash in as it’s right near my loo.
as for my meds my partner would check to see if I had taken them ,I have blister packs but now I’m forgetting to take my meds  and as some are anti depressants I shouldn’t be missing them.
and I’ve been left with the finances to do now such as making sure there is enough money in the account to pay the bills and that is stressing me out.
at my assessment she didn’t even look at my knee about from asking me to do a very slight crouch basically just by bending my knees a bit but in her report she said I crouched down and got back up .if I had crouched down I wouldn’t had been able to get up without holding onto to something . 
And this walking more than 200 metres yes I can but every step is so painful but what choice have I got my consultant said try not to use walking aids so I don’t this is because walking aids can weaken your knee even worse as the muscles aren’t working so well.
so for example I have to go to the bank in town .nearest car park is a small one always full with shop workers etc cars. So the one where I can park is quite a distance to the bank it’s painful walking there but walking back I’m almost in tears because of the pain .but to the dwp as I can walk it it doesn’t count how much pain I’m in. I’m to young for a knee replacement I’ve been told .i can’t take anti inflammatory meds because they upset my Ibs.
the injections in my knee didn’t work.
ive sent off my mandortory consideration letter but I don’t think they going to change their minds as they scored me no points.
but do you think I ought to tell them I have not got a carer now to help me . 
Would it make any difference ? I don’t think I can ask for another assessment just have to go through their process.