Hello Autumn, you have definitely come to the right place. Your story is very common and so much like mine and many others on this site. I read your profile and it sounded like much of my life.
I am a 64 year old MTF and have been on HRT for 18 months. I came out to my family when I was 60; so you are not too old to transition. One of my friends started her transition when she was 72.
If you have not already you should consult with a gender therapist. This person can help you to get started on your transition. Depending on the area you are in most endocrinologist will also require you to get a letter indicating that you are indeed trans and you would benefit from HRT. Many of us are also open to chatting with you via private message to answer your questions in more detail. Pick someone that responded to your post and send them a friend request.
Most of us experience severe gender dysphoria and depression, with thoughts of suicide before we start HRT. Usually within a short period of time after we start hormones (for me about 3 weeks) we can feel our emotional state smooth out. Before I started HRT I felt like I was bipolar; my emotions had big fluctuations every day.