If God made you and God doesn't make mistakes then the person you are (trans and all) is perfect, just as God intended. So why would any human try to change who you are?
Everyone I know who believes in the afterlife believes we leave behind out body when we enter the afterlife. What we take with us is the core of who we are, our person, our personality, our essence; however you want to describe it. Within that core is everything that makes us who we are and if you're trans, that's part of the package. And if you believe in "God the Creator" then that core is what God created.
Toss that at your therapist and see what the reply is.