What do I do now? Plz help!

Ok, first off thank you for looking at this. I have a batch of mead that has been fermenting for 3 weeks now. Still bubbling smoothly. I did some research before I began but obviously not enough. I don't know what to do now and after asking guys at the local brew shop I am left more confused. It sits at 1.050 right now( a 5 gal batch with 17lbs of honey ) and I have 1 more week before the recommended transfer to secondary. I bought a "wine whip" for degassing. I am aiming for a sweet mead, I am told I should get it as close to 1.000 as I can and back sweeten accordingly.
1) should I leave it in primary for longer than 4 weeks>
2) when should I degas it?
3) when do I stabilize it?
4) and how do I effectively back sweeten?
any answers would be so greatly appreciated guys.

1) I understand why, as a beginner, you want to follow exact instructions. But honestly mead is not about dates/weeks. You don't rack to secondary until it's close to its final gravity, no matter how long it's been in primary. You will not get any off-flavors from leaving it in there another month or two
It sounds like it's being a bit slow. You're not keeping it too cold are you? Did you pitch enough yeast? Did you include any nutrients or fruit?

2) Mead takes so long it doesn't normally need degassing, but you'd do this once it's finished fermenting and the gravity's not changing.
3) Add 'sabilizer', or more exactly, sorbate and metabisulphate and leave for a few days.
4) After stabilizing add some more honey until the gravity/sweetness is where you want it. After a few days check the gravity's not changing to know that the yeast hasn't sprung back to life. Alternatively you can add artificial sweetner, which doesn't need you to stabilize.
Note that adding more honey may introduce some haze to the mead again which you'll have to wait another few months for it to clear again.

What yeast did u use ? What u need to do is just let that sucker ride it out , 3 wks is a blink of the eye in Mead world. You most likely started with a gravity of ~ 1.120 so 1.050 means ur still riding the right track. your at ~15 % abv

Don't transfer till its clear and stable ( multiple gravity readings reading the same) 1.000 will leave u at a dry mead.

Reference: 0.990-1.000 = Dry
1.000- 1.008 = med dry
1.008 or greater = sweet

1) yes , mead is unpredictable as far as time is concerned. Hydrometer is ur best and only friend.
2) Probabley no need to.
3)At first racking , then every other after that. Wait one to two weeks before you bottle.
4) Once your stabalized add honey to a bit of water and add to mead ... to taste.

If you don't want to keep taking the gravity: I generally wait until the mead starts to turn from that 'milky', yeasty colour, to a deeper/darker brown colour before I rack.
This is the point where the bulk of yeast has dropped out and you gain most from racking. If you rack too early you end up with a lot of lees just a few days into secondary, since most of the yeast is still fermenting-away and gets transferred.
My 2 cents.

Thank you all for the info. My mead has come down to 1.040, color is similar to lemonade, still slightly cloudy. When I pitched yeast I pitched the whole tube of White labs sweet mead yeast(WL700) and nutrient, I added additional nutrient the first couple days of fermentation and kept the mead wrapped in a beach towel and t-shirt for temp regulation and darkness. I'll leave it in the primary until it gets close to 1.000 and back sweeten once its in the secondary. It is still bubbling steadily, about once a second. Any additional info you guys may have is greatly appreciated and written down for the next batch, and again thank you very much for the info given already it has helped tremendously.