Everyone has these issues and concerns. This is serious stuff! Your family is concerned about something drastic but they have not walked in your shoes. My wife was really against it at first but over time has come around and is just concerned. I personally have waffled on the decision but in the end realize there are three things that impact my decision.
First, if I do nothing different I will continue to be overweight. I've lost weight in the past (a lot of it) but it comes back. Hunger is powerful motivator. It is primitive emotion, just think of the animals around you. They will always eat if given the opportunity. What keeps wild animals thin is not metabolism but rather lack of excess food. Hunger will always drive you. Yes some people can eat as much as they want but we ain't them! The first year hopefully I will be able to divorce eating and hunger from each other and learn there is a difference between the two. I will learn to not eat all the time. I am a diabetic that is weight controlled for now but I know it will slowly become a problem if nothing is done.
The second factor is volume. I know I will not be able to just anything I want at the volume I want. Our stomachs are designed to expand to work in a feast/famine world. The problem is now there is no famine for us, just feast. By severely reducing the volume I can eat at one time I will not be physically able to consume, consume, consume. If I try to consume to much it will come back out. I imagine the is not pleasant so I will naturally try to avoid it. It is not worth shoving food in to throw it back up.
Third is dumping. My research is that the things that cause dumping are those food you want to avoid anyway, RNY or not. My sister has the sleeve (so not as likely to dump) but certain foods disagree with her. For her it is just not worth the discomfort of those food. Cakes and bread are a problem for her. Much more than a bite or two she knows she will have a problem. Just not worth it for her.
I guess a forth one for me is the type of surgery. I am not really a good candidate for a sleeve since I have GRD but the success rate of the RNY is so much better. I always look at the average (not the best case, not the worst case) and the RNY weight loss is significantly better at getting close to ideal weight.
My last thoughts are these. Give your family time to come to terms with it. It has taken me months to resolve this in my own head and just as long for my wife. I was able to articulate that I wasn't doing this look or even feel better. I am doing this for my health. I want to have a higher quality of life for longer.