This breaks my heart. I am so sorry, Carlita.
I'm sure this is not something you haven't already thought of, but I'm going to go ahead and say these things anyway, just in case something I say might help. Here's my thought on the how/why your daughters could react that way, only because looking at the reasons may give you a leg up on helping your son, and maybe (with much luck) eventually your daughters. I think the reason is, they see hurt and disruption (in their mom's life, and in their own) and they don't understand gender dysphoria, and so it is easier to blame that hurt and disruption on you, than to see the root causes of it lay in both the random lot of life (like having a loved one born with MD or any other major life-impacting condition) AND (most importantly, because this is the one thing they have a chance to improve) magnified by their (and their mother's) own choices of how to respond. In the position of being a family member, it sucks to have a loved one being treated for cancer, but your life will suck a lot more if you get angry at that loved one for the difficulties that causes everyone, and start treating them poorly, and cutting them out of your life, and placing all the blame on them. You can tell yourself that person is ripping your family apart, but in reality it is both the cancer, and even more-so your own reaction to it, that is doing that! The blame is a poison that you can choose to feed, or not, and it can destroy your relationships if you choose to let it, or not. Learning and becoming educated about the condition your loved one has, and coming to recognize it is not something they are at fault for, is vital to helping you be able to deal with it well in your life. I am the wife of someone who is transitioning, and we have children, and I can say to your family that my experience has been that it need not destroy relationships, and that if you truly have or had any love for your family member that is transitioning, then the best thing you can do for yourself and your family is to learn about and come to an understanding of this, and try to help everyone deal with it in the most positive fashion you can. Blame and bitterness towards the transitioning family member will do you no favor, and robs everyone.
If you can point this out to your kids, let them know you recognize how difficult this is for everyone, and wish more than anything this wasn't the hand you or they were dealt, but that you are doing the best you can and will always be there for them with love, and hope they will not let bitterness and blame win out...at least they will have this idea planted in their minds that may eventually speak to them as they are grappling with their reaction to this.
I would probably write all the things out that I would like to be able to say to my son, all the thoughts that if things go badly I might not have a chance to say in the future, when I talk to them, all the "counseling" so to speak that might help him have a way to better deal with this, so at least they will have access to your thoughts in some form, that they may not be able to digest right now, but may help them in time. Continue to have a strong, unwavering message of love, as that has the greatest chance of at some point winning out over fears, hurts, and bitterness.
It is unfair that gender dysphoria is still so not understood by so many, that people going through such h***, are treated so poorly and put in the position of having to try to be the strong & forgiving ones, for all around them. But parental love *can* have amazingly selfless capacities, and it often is sure put to the test.
I know that it is a small consolation, but my heart is with you.
