Hi Andrew,
I’m sorry to hear of your situation. You should definately seek professional advice as you have too much to lose by making the wrong decision. You might be lucky and only lose your deposit, but many contracts allow the developer to pursue for costs incurred in reselling an apartment (including any shortfall between final sale price and your contract price!). I hope your’s is not like this.
Talk to a professional.
In the meantime, I’d be happy to check over your spreadsheet. Email me.
Good luck,
F.