Had a bloke do the same thing on a Triumph Motorbike...bought a bobber over the webz from photo's for $12K. It was only a 500cc twin and a mish mash of parts...sum total worth of the bike was maybe $1500.
He bought it to me with a death knock...the big end was gone and about to throw a leg out of bed.....and he swore black and blue that the bike was fine 'just needed a tune up'. Said the bloke selling it told him it was just rebuilt... but no receipts? I tried to get him to churn it, cut his losses, but he wasn't interested.
Eventually I convinced him to let me at it....and another $5K later the bike is running fine and has been for a 18 months now. But he still has a $1500 bike that he paid $17,000 for.
Poor bugger.
Anyway, off topic....but it can be done, GTSBoy has given you a good map. Do what you can as you can afford it, prioritise and address the immediate stuff first. You will get there. Plenty of good help on this forum, you're not alone 34Red.