I think it's a mix of what you feel comfortable with and what you think those around you (that you care about) are capable of feeling comfortable with.
Chances are if you are confident in your decision and you have done your research, then you are likely making the right decision for yourself. While I think it's important not to abandon the concerns of those that care about you, it is important to address them with the highest amount of consideration.
Make it easy on them. Maybe (if possible) instead of making it such a discussion, you do your research and then let them know when it is already set in stone. There might be a short blip of turmoil in their eyes, but your confidence and forwardness in the matter will show and that builds trust.
Sometimes it can be dangerous when there are too many cooks in the kitchen. The same goes for your own life. While it is so incredibly important to have the support of others, it is (as others have said) extremely important to do what you need to do. The key is minimizing the impact on other people.
These kinds of decisions sometimes take a lot of tact to get others that are close to you to accept.
I will use myself as an example. Every time I have done something, I haven't told anyone about it until I already made an irreversible action in that direction. I didn't come out to anyone until I had started hormones, I didn't tell my parents about my voice surgery until i'd already paid for it, and same with the FFS procedures I'm about to do.
Allowing them to suggest against what I've known I needed to do would have just complicated matters. Yes it was hard for my mom to accept that I was going to travel to South Korea to have my vocal cords operated upon, but she got over it in less than an hour. If i would have tried to earn her trust beforehand, it could have gone on for months of her trying to talk me out of it.
In the end, you just have to keep moving forward. Minimizing the impact on those you care about will be a great reward for everyone involved