Obviously one is fear. I am 30 years old. Am married and have three kids. I’m worried about my own future, as well as the future of my closest.
I hope you get support from them. I started opening up to my wife after one of my kids was born because we had a lot of arguments, we went to therapy and there at the end we discussed a lot of things, one of them being I was extremely dysphoric during her pregnancy, and even after that, I felt a lot of pain. We talked about it, she was very supportive on the topic, we made an agreement that I start transitioning when it's required or at latest when I'm 40. When I was 36 she kinda pushed me to start transitioning, I was in a bad a shape in all possible ways. That was years ago. Both kids and my wife are very supportive, we are all happy, and NONE of us would ever consider revert to "the old life". Even when local politics and government forced me to stop taking meds (jailed one of the doctors who did care about us), when they passed bills to criminalise my existence, I was thinking about aborting it for the safety of our kids, and life. They were still there and supported me, and they told me don't even think about it.
tl;dr: 30 years old is NOT old at all. I hope your family supports you like mine did.