It appears that your excuse for not paying back the money is that you don't have it right now and that you never made any money with the money you borrowed.  But the terms were clear and you now are agreeing that you owe the OP 0.9 BTC.

In the other thread, the OP gave you an extension and you said that you would give him "everything in your wallet" that you had at that time.  So you now owe him 0.9-(whatever you gave him).  If you can't afford it, you need to at least show a good faith effort to work it out with him.  The OP seems to be a reasonable person giving you extra time for free when you requested it.  Now is the time to man up, face the music, and work something out with the OP.  The agreement was that he gave you 0.7 and you would give him back 0.9.

Perhaps you can work out a payment plan?  You say that you made 0.05 during the month that your loan was extended.  Perhaps a reasonable plan may be to pay 0.05 BTC back to the OP for 12 months (in effect giving him 0.1 BTC additional in "financing charges/interest"?  This seems reasonable to me and if you work out a plan and stick to it, you won't be labeled a scammer.  Everyone falls on hard luck from time to time--that's why no one gets force into bankruptcy immediately on losing a job--but you need to show a good faith effort in trying to repay your creditors.  You incurred a debt, and you can't just snap your finger and ask everyone to forget that the debt exists.