Much of what you are saying is pretty common.
You may have to educate your mom, but it sounds like she is trying, and that is a good first step. Talk to her, and be gentle. I'm not saying it will go perfect, but talk to her. It will be a while before you can get on hormones, much less see changes. There are steps and hoops to go through first. Learn about it, and read about others experiences more so you can share that information with her. As you go along, your parents may open up to it and actually help you. You do not need to live as a woman before starting hormones, usually you start them first, then start to live as a woman. You need a therapist first, who will need to get to know you and they will get you going down the path and can help sort out family issues as well as many of the problems you will encounter.
Realistically, there is really not much you really have to miss out on. In terms of kids, you can use a sperm bank, it's not THAT expensive. You can still get married, and things. It is not like you are being banished to another planet. Don't discount kids, as you become more yourself, you may really want them later, so either sperm bank, or remember there are lots of great kids who need parents to adopt them.
As for trying to keep the peace, many have done that. At some point you may just say it's no longer worth it and do what you need to do. Until you reach that point, you may have a hard time with this.
Lastly, your size is not an issue, while not that common, there are women of your stature. If you are muscular or overweight, losing some will decrease your shoe size a bit (in case you are curious) and some people do experience some height shrinkage on HRT, 3inches seems the most you can hope for, and 1 is more common. So you may lose a shoe size or more in the end. There are places to buy larger shoes of almost any style you want, and places that can make a copy of any shoe you want in any size.