I am sorry to hear that

I understand you concern about possibly loosing your children.
Aside from your gender issues does your wife take your feelings seriously?
You are absolutely NOT a freak!
I don't know you or you wife so the following is only conjecture and my personal opinion.
Your wife is afraid to loose the man she married and so her reactions seem to come from that. I'm sorry she won't go to the therapist with you. Is she at least talking with someone/anyone about her own feelings? This is a lot for some people to wrap their head around. My wife was afraid that I might be gay since she dated a young man who "came out" while they were dating (for example). Perhaps your wife has something in her past that she hasn't (or won't) deal with that has amplified this issue for her.
Communication is the best (and sometimes only) defense in these cases.
Do you know what your wife is feeling right now? (deeper than just her reaction)
We need to remember our choices affect others and sometimes in ways that we had not anticipated.
My advice is to talk to your wife about her needs/feelings (not necessarily about your transition), so you can show her that you still care about her needs. This may lead to a more stable "foundation" so to speak from which you may be able to handle your transition together.
My heart goes out to you both. I wish you the best.