Good luck in your new space!!
Attending a Trans peer support group is the single best thing I did for myself after my breakup. My only regret is that we only meet every two weeks... After a few meetings I started to get involved in the local Transgender community and made new friends quickly :-) Transition takes time, lots of time.. Things WILL get better for you... they did for me.
I don't know how old your son is... Mine is about to turn 5. After speaking with a few therapists and other Transfolks, I found that young children tend to group all of their worries into one. Often, they get the idea that one action might fix all of their worries. My son misses our family living together, living in our old house and doing things together. Sometimes he'll say that he wants me, "to be a boy again," or he'll want me to cut my hair.. When he's said those things, I'll follow it with, "What do you think would happen if I was a boy again?" He'll say, "Then we can all live together again."
I guess what I'm trying to say that your son is probably more upset about the breakup than you being Trans. Kids tend to understand the notion of Transsexuality more easily than adults. I was playing with my daughter, 7, when a few of her friends came over. She introduced me and simply said, "This is my Dad, Jess..... She used to be a boy but she's a girl now. All three friends looked at me, shrugged their shoulders and said, "Oh... Okay .........Wanna ride bikes with us?" They just accepted it. It's unfortunate that you have to deal with the divorce stuff on top of the Trans stuff but you'll survive. It's important that you talk about it, though... reach out to people when you're down, even if it's just a text or a chatroom.
Hang in there!