Didn't read the thread all the way through, but non-supportive family is a very common obstacle. Often it seems to be because the family has a lot invested in an unhealthy lifestyle and see someone trying to improve as a rejection of the lifestyle *and them*. And it hurts and is a major obstacle to overcome.
I spent last week sitting with an old friend who had quadruple bypass surgery. His wife loves him but cannot see that she has become part of the problem by enabling his unhealthy food and lifestyle choices... and it is starting to harm their kid as well.
I wish I had a positive thing to end this with, but all I can think of is the following advice: seek counselling for the whole family. It doesn't take too big a change to make things better.
Good luck!