HI! I am in a similar situation only I did have complications with my BAND.
1st I would like to say that you should go to get your band unfilled. If you cannot get veggies and protein down then you are too tight. I know that all to well. If you continue to throw up you WILL end up with complications that will make a revision more difficult but not impossible.
2nd There are two types of surgery for WLS. There is purely restrictive (Lap Band and Sleeve) and there is malabsorbitive (RNY and DS).
If you have not done well with the restrictive surgery, then you may want to consider the malabsorbative option.
So you ask if DS is a good option for you? Any DS'er is going to tell you it is a good option so you want to look at the long term data and the side effects and the risk of complication and risk of death and decide what is right for you. Every surgery has its down sides.
In the end YOU will be the one to live with your option and you should research heavily before choosing.
That being said, there are a lot of successful people who had high BMI's and had the DS.
From what I understand you can eat more with a DS because they dont make your pouch as small as an RNY but you absorb less calories than an RNY'er. That would be biggest plus, I think after having the band and not being able to eat for 9 months myself. Also the DS has a higher long term success to keep the weight off from the data I have seen.
But that being said as well. I have chosen the RNY because I am not willing to stomach the higher death rate and some of the side effects that come along with the DS. But I am willing to restrict more of the food that I eat and live with a small stomach for the rest of my life. It is all what you are willing to do and deal with.
It is a personal decision and I hope you can find the choice that is right for you. You are young and will have the rest of your life to live with whatever decision you make and either the DS or the RNY would bring you well below a 51 BMI.
GOOD LUCK