You're not sick or delusional. You are who you are. Simple as that. However, I'm not of the opinion that your sponsor needs to know "everything". If your sponsor isn't the right guy to tell, then find someone you can tell who won't judge you. There are plenty of LGBT groups out there who can lend support. There's no need to go through this alone, but at the same time, you always have to ask yourself "Is telling a guy who may not understand -good for my sobriety or bad for my sobriety?"
If you know or suspect he may not understand, it could be bad for your sobriety.
We live in a time where it can be dangerous to be trans and I hate that it's like that. My addiction counselor and my daughter's therapist is trans and she's one of 2 people out of dozens of mental health professionals who has ever been able to help me. She was also there for my daughter when she first came out as gay and then as bisexual. That woman saved my daughter's life and her contribution to my sobriety is immeasurable. She specializes in PTSD and substance abuse and she's also a combat veteran. If you need some assistance finding someone in your state or country, I can get some information from her. I see her tomorrow. Just let me know.
My advise to you would be to find some therapy with someone who can help you with gender affirming care. People who are on the fence about being trans often just need to sort out those feelings. It doesn't mean you have to transition to a woman or anything like that, but you owe it to yourself to sort it out with someone who won't judge you and can advise you in a healthy, professional manner how to address this.