I agree with your concerns about the afterlife, that among other things keeps me going. The other thing that I've found keeps me going is that I do want to experience life as a woman. No I can't go back and be born female, that ship sailed almost 40 years ago. I don't believe in reincarnation either and even if I did, how could I be certain I'd come back as a female human? The fact is after these 39 years in the wrong body, I want to know what it's like to be in the right body, in the right role within society. What is it like to be treated like a woman, what does it feel like to actually be able to act as women are expected to act, what it's it like to interact with other women on a peer to peer level?
Do I feel trapped, yes, many times. However, I know there is hope of something better. I get anxious wishing it could happen tomorrow and knowing it won't, but I also know that if I keep going through the process eventually I will realize something great in my life.
The same can go for you or anyone else feeling the way you do. There is some hopelessness in our situations but if we can push through that temporary feeling, we realize there is much to look forward to.