Re: Stopping bf in front of non-supportive people
I started to get more uncomfortable bfing in public the older my daughter got, too. Before she turned one I'd whip it out pretty much any time any place, but once she was a toddler it just seemed like a different situation. Babies have to nurse and they need to do it whenever they are hungry. Toddlers are different. I would still nurse my toddler around family or if it was necessary (like if she got hurt or if it was bed or naptime), but generally for a toddler it isn't necessary to nurse at specific times because they can eat other foods, other beverages, and understand the concept of delayed gratification.
At your son's age it is perfectly reasonable to expect him to understand nursing limits and to learn to wait until you are ready to nurse him. I would say things to my daughter like, "No milk right now, let's wait until we get home. Let's have a snack/a drink of water/play a game." Most of the time she would be fine with the distraction, but if she got really upset I would find a place I could nurse her.
Good luck with everything. Setting limits doesn't mean you are hurting your child in any way, you are teaching him discipline just like you would in any other situation. I have not read this book, but I've seen others recommend Mothering Your Nursing Toddler. Perhaps something like that might give you more specific tips about developing a nursing relationship that you are both comfortable with.
“We are not put on earth for ourselves, but are placed here for each other. If you are there always for others, then in time of need, someone will be there for you.”