If you could get the official rate for your pesos, there'd be a hundred threads here on how to do it. Forget it.
To use dolar ahorro, you have to get authorization from AFIP each month, using your CUIT or CUIL (if you can do it, you can get the authorization online, quickly and painlessly; print it out and bring it to the bank). You can't get the dollars retroactively, from previous months. You have to be making a bit more than 11,000 pesos a month to qualify, and since you're not working now, you may not be able to do it at all. But you can at least give it a try. If you can do it, it will be the best rate you'll be able to get, even with the 20% added. I believe that you also have to have the money in an Argentine bank in your name.
To determine how many dollars you can buy, the AFIP averages your prior 12 months of earnings and allows 20% of that amount to be used to buy dollars. As of a month or two ago, you could buy the dollars at some casas de cambio, for an extra 1% commission, but I believe that you still have to have the pesos in the bank in your name (not 100% sure on that; haven't tried it). Search Clarin or La Nacion (using google: e.g., casas de cambio dolar ahorro site:lanacion.com.ar) and you should find out which casas de cambio accept the form from the AFIP.
If not, probably the next best idea is lacoqueta's. Buy the BONAR 2015 and you can get your dollars here in October when the government has to pay it. The last time I could find out anything about it, that was the second best rate you could get (and probably still is), but you'd probably have to set up a brokerage account to buy bonds (I don't know the cost of the bonds) and as an extranjero you probably can't open such an account, so you'd probably have to have your girlfriend do it. I don't know what the commissions are, and they may give her trouble about the source of the funds (you know how tight the money laundering laws are here for non-politicians and non-narcos). If you can buy Argentine bonds, you can buy them and bring them home with you, but you might have trouble cashing them out until the problem with the hold-outs has been resolved, whenever that may be, and the longer you wait to cash them, the higher the risk of not getting a good rate (or, with this country, getting paid at all).
All of this presumes that you are dead set on cashing out. Otherwise, all the other ideas suggested are very good as well. And in any case, you may not be able to do any of the above.
By the way, if Scioli does really well in the PASO tomorrow, you may see the dollar blue jump another 1 or 2 or 3 (or more?) pesos in the couple days after.
And the official dollar is up a full peso since October, and despite what Kiciloff it telling you, inflation is alive and well (and beginning to accelerate again) and eating the purchasing power of those pesos on a daily basis. Food is going up at a ridiculous rate.
The point is, if you want to get rid of your extra pesos, sooner is definitely better than later.
De todas maneras, estás jodido.