Trangender advice

I know this is probably not the best place to post this, but I don't know anywhere else to possibly find answers.

My cousin who is biologically male wants to live as a female. I try to be supportive, but honestly I don't know anything about the things he is going through. He told his mom how he felt and she doesn't want to talk about it or see it. That breaks my heart. But he thinks he wants to go ahead with hormone treatment, but bind himself on "guy days". My advice was to talk to his Dr, is there anything else I could say? Also, he claimed that last month and this month he got a "period" no bleeding, but felt gross without a pad on and cramped for a week. Is this normal? I love him and I want him to be happy and live the life he wants, I just honestly don't know if I'm saying the right things or not.

Note: I call him by female pronouns and by his chosen female name. Thanks for any advice.

If you have negative things to say about my cousin, please keep it to yourself. I understand that not everyone agrees with his choices, but I don't need to hear that, I just want to know how to be the best support system for him that I can be.

Caitlyn: My cousin hasn't started hormones yet, that's why it confused me. Possible that it's the same thing as when woman want to be pregnant so badly that their body starts exhibiting symptoms?