Parents are so close to finding out, I need support

So I foolishly thought that I could hide the voice change from my parents. I started T like 5 months ago in secret. They don't even know I'm trans, much less gone through the process of getting T legally. I'm 18 and about to move out in a couple of months

Today my mother asked me if I noticed my voice cracking and going dry. I said no which was a mistake and then she told me that I sound like I'm going through voice mutation/change. I laughed it off. She suggested going to the Endocrinologist and I said I already have an appointment which is true. I don't want to come out to them mainly because they hurt me all my life and sharing something personal with them feels awful. I don't worry about them disowning me, just having my identity used against me like they did before with other things. I don't know if there's something I can do to hide my voice change. I don't have a support system so I just want to get any kind of closure or advice