Not come off like too much of an ass, but first of all, this is really not the right place to be asking this question (I'd think SuperUser might be a more appropriate site) - this site is for professional system administration - and secondly you're probably basically screwed.
Before you throw in the towel, you might want to search for tools to recover data from a damaged RAID array. I'm pretty sure you're using software RAID, and a quick Googling revealed a large number of options for software promising to recover your data. Might want to ask around about which ones are any good, or if you have other options specific to the consumer-grade product you have, but that's best done somewhere else, like SuperUser. Beyond that, you're looking at thousands of dollars for professional data recovery.
Other than that, the only thing I can recommend you do about this situation is learn from it.
Software RAID is awful. Never use it. For anything. Really, this is why - there's absolutely no redundancy built into the system. Your config/array gets an error, you're outta luck. At least with hardware RAID, configurations are present on both the controller card and the disks, so you can do something if the controller (or the disks) run into an error with the array.
RAID is not the same as data protection or backups. There's a saying in systems administration that data you don't backup is data you don't care about losing. For a consumer-based solution, at the very least, copy your data over to a high capacity external drive every so often, and store it somewhere safe when it's not being actively used.
In general, RAID5 is a bad idea with large disks, especially large, consumer-grade disks. It doesn't offer enough redundancy, and you'll often run into issues where either a second drive fails during the days it takes to rebuild an already failed drive (so your array is dead), or you'll run into bit-level errors if you ever do need to rebuild it (so it won't rebuild, and your array is dead). In your particular case, you basically sacrificed a third of your drive space for no benefit - you wasted a whole 2 TB drive and are probably worse off. If you had all three as independent disks, and one failed, you wouldn't be in a spot where ALL your data is at risk.
My advice for next time (and this is from a guy who has a ~10 TB RAID array in his desktop at home) is:
First of all invest in a "RAID Adapter Card." I use an Adaptec that lets me put 8 disks in a variety of RAID levels, performs like a champ, and doesn't chew up system resources to maintain the array. (Hardware RAID cards have memory and small processors for this very purpose.) It's gone about 5 years without a single hiccup too, as an added bonus.
Second of all, consider what you're actually getting for the money you put in. Like I said above, you basically threw away the money you spent on that 3rd drive, and ended up getting a system that's slightly worse for it (system performance suffers, you've lost all your data instead of just a portion, etc.). Look at maybe getting a small NAS drive, such as the one I bought for a technically less inclined person in my life - 4x 2TB drives, in RAID 0, 1, 5, or 10, plug and play and accessible over the network, for several hundred dollars. (Buffalo was the brand name, I think.) Or you can do what I did and drop a couple grand on a proper RAID array, if it's worth that much to you. Everything in life has a value, and everything in life has a cost. What are the actual benefits of what you're doing (RAID), and what is it costing you? Is it actually "worth it?"
Finally, take a little bit of time to understand the limitations of the system you're setting up. RAID is not a backup solution, so what happens if a disk fails? Two disks? The controller card? What about a house fire? (etc.) What can you do to mitigate or remove those potential pitfalls (such as some sort of backups). Think ahead a little bit now, and save yourself a lot of pain later.