You need to take the time and financial resources required to get through this. And that is how you can explain it to your wife.
This process is difficult for everyone. Many times our loved ones feel like we are being selfish because we are dragging them through this. Also, if your spouse has never had to support herself or family or has tremendous fear of change, there is a lot of anxiety and anger, because the peaceful life is being disrupted.
In my case, I've sacrificed my life for others my entire life and have slaved for my family so that they are well taken care of. So, being trans* is extremely upsetting because now I am the one with problems and am not the solid, strong person taking the lead. So it has been really difficult for me to even go to therapy, because I feel like I am taking money from the family. But I realized eventually that I need to be good to myself, otherwise I am good to no one. Particularly if I have a mental breakdown. How will I go to work?