Hello Kayla. I understand you well even though it took me to get 23 before I transitioned but I still lived with my moms. I did the same as you, sneaked a pill here and there from my mom for relief, but of course that was not the best way - it did not help anything long term and as I understood it later was a bit dangerous, medically speaking. When I did medication later, I can say that indeed it was a huge relief for my mind and body. another such huge relief for me was to drop the pretense of being a male. I was not out at that time, but I dropped the parts of my behaviour or personality that I only used to pretend to be a "regular boy". From that time on I was of course seen more as a strange guy, maybe gay, but I did not care, I was more "me" and was gendered female at times by strangers just from that - that was amazing - I did not do any physical changes except some eyebrow plucking and very close and frequent shaves.
Back to the topic of hormones and getting into therapy. I see two options. One is to actually meditate, "girl up"
and come out to your childhood doctor about this. He should be a person you can confide in, it is not that you did not tell your parents already, so even if he does tell them it is no news. You cannot loose anything by telling him about this and that you seek help about it. Possibly he is a good doctor and sees the need for doing something about it and either get you into therapy or talk to your parents about the seriousness of it.
The other thing is to just be persistent for your parent. Nag them, insist that this is an issue for you. If they really get annoyed, tell them you want to go to a therapist and talk this through, but make sure it is not going to be some nutcase fundamentalist christain therapist or some other freak who wants to cure the TS out of you! Ideally of course you should try to make it a gender therapist as these guys are obviously experts about this sort of issue, so you can maybe convince your parents to choose that. It is ok to let them for now think that this is just a "phase" or a temporary issue that still has to be dealt with by a gender professional. Once you are at the therapist, you can be open to him about everything.
I hope you can make it - those early years are so crucial for transition - every year counts there to get into therapy, transition and eventually medical treatment.
