I applaud your actions in support of your son.  Yes, you may need to rethink a lot of the dreams you had for your child and their future.  One thing to remember, he is exactly the same person he has always been inside; you just know him better now.  Blessings to you both!

And EX parents have nothing to do with your family.  You live befor them and you will live after them .

Your son is young.  Mental health,,therapist is a good place to start.  But actuall surgery is a no coming back from.   I would insist that he. Delays actuall surgery until he . Dresses and lives like a woman for some time year or fwo to make sure this is the life he wants to live his life.  

I'm glad your son has a good therapist who deals in this.  Ideally we want to help out m our children financially as much as we can, but realistically the amount of money your son will need to invest in this is going to be large, potentially.  I don't think it's wrong to have him start working towards his goals knowing financially it's going to be an investment. 

However, I would not allow any hormone treatements, puberty blockers, or surgeries for a minor child.

Just me. But.... if a child wants to take body destroying steps, they should have to make that happen once they are adults.

We have a gay adult son, but not a trans child.  I am sure that this has to be an incredibly hard thing for a parent  to work through and support.

Your son is lucky to have you. It's a lot for a parent to unpack. I believe that gender affirming surgery is life-saving. The stats and research are clear in terms of the severe depression and/or suicidality in transgendered people. Your acceptance and unconditional love come across in your post. I don't know what the costs are, and/or what your resources are, but I would urge you to help him in whatever way makes him feel whole and seen. 
 

ETA: that should read whatever way you can afford to. 

This transition gets easier. YSK is trans, waiting to turn 18 so they can start physical transition (not legal in our state anymore for minors, which infuriates me to no end). Now that I have new insurance, I'm hoping we can find them a new gender-affirming therapist. Their last one switched to providing care to younger kids, so YSK has been seeing what I call a "stop-gap therapist".

Yes, it's a lot to unpack. The best thing you can do is educate yourself and be a real ally to your son. There will be a lot of a-holes in this world, and he'll need you to go mama bear on some of them eventually. Just keep yourself informed and find other parents to talk to for support.

Is top surgery will likely work. Depending on the amount of money you spend the better the result in scaring. If they go through the arm pit the scar is there and not noticeable.  If they just cut at the bottom then there big scar. What will be noticeable when naked.  
Bottom surgery on femal to mail. Difficult it's a removal of all female organs.  Major surgery..  and the fake man parts never look real. It's can not function sexually.  You have something to make it hard. Rod.  Most likely not get that feeling and will not get that happy ending 

'So he must really look into it. How he wants to be seen naked.  And the vast majority of woman will not want someone who can not have children with.  Many problems to work out.  My daughter was a lesbian. The just majority of her lovers. Decided later on. Not that much latter in.  
They want chrildren and the life that look normal ['even though I really can't be normal]  Found a man got married and has kids.  Even through a few years before it was life in a woman to woman relationship.  My daughter was the  male there other woman were the female part so the getting married etc part was somewhat normal for them.

Neither of Husbands daughters seem likely to produce grandkids right now, and SD17 Powersulk was previously very masculine. Ive broached the topic and she tells me she eventually wants kids, and identifies as female, however one never knows because she was also chopping off her hair and wanting chest binders.