I cannot thank you all enough for your kind words and fantastic advice - this has really reassured me and given me so much excellent advice; bad news for you as you will never get rid of me now! 
@Yimmini, I see your point - that could be any outgoing and there could be any amount left. Thanks for this, and for the reassurance that the applications will eventually not count. I guess to a certain degree improving a bad score is a waiting game. 
@Eminybob thanks so much for your advice on this. apologies if I have been unclear; there is no formal agreement whatsoever in place, and in fact this particular family member has been so kind and accommodating over this, but that is part of the reason I want to stick to a 'plan' (for lack of a better word!) which will slowly go up as I get into a better position and get rid of other debt. Hope that has clarified 
Hi @Regina (great name) no, my credit card debt is still with the CC companies themselves and is manageable - i have never been on a debt plan (close call at one point!) and have never missed paying at least the minimum repayment. I would imagine they would ask about what will then be £400 going out of my bank every month, so I'm thinking it might be better to just disclose that up front rather then look like I'm hiding anything, if that makes sense? By Dec I'm planning on having £1422.83 left on CCs and owing £6479 to the relative; do you think this would make a big dent in what they would lend us? Also, I don't suppose anyone knows if I would need anything in writing from the relative for the lender to know what is left, or would they take my word for it (I realise how naive that may sounds - sorry!)
Yes I think you could well be right, that there isn't much other activity and that's why it is still showing. Is there anything in particular I can do to try and get it up again quickly, other then just paying off as much as I can, as soon as I can?
@lottie thank you SO much - you have no idea how reassuring I found your message and how much I needed to hear something like that! I didn't quite realise how anxious I was about all of this until I started talking here about it - money is such a weird subject isnt it?!
The lenders will see my score, won't they?
I haven't ever had a late or missed payment so that should stand me in good stead
That's really reassuring - when I got back on top of everything it seemed totally impossible, but I am slowly chipping away!
Will the fact that my partner has great credit and no debt make up for my issues?