Check your HOA regs and your city/ county zoning to make sure that having a roommate is allowed. Some HOA regs do not allow you to rent out space to a roomie -- all occupants must be "family" members.
Personally, I vote for selling so long as you can cover the cost of a realtor -- perhaps contact the realtor who sold it to you and see if s/he will list it for a discounted commission. Any loss you take on closing costs or fees, I'd chalk up to what I call a "stupid tax" (we all make mistakes!) and realize that if you cut your housing cost by $2600 a month, you'll make it back quickly.
If I were single, young, and childless with that kind of SL balance then I'd spend two years living in the cheapest, closest-to-work, non-crime-ridden part of town I could find and pay it off like my hair was on fire. (And FWIW, I have a similar SL balance but have a teenager to feed, shelter, and keep in his HS district, which is the only thing stopping me).
One goal of Mustachianism is to live simply and modestly thanks to a strong frugality muscle. I think it will be very hard to fully understand/ adopt this philosophy while living in swank surroundings, so selling also puts you in a better environment to change your frame of mind in ways that will benefit your long-term future.
