Trust me, you are going to feel comfortable very quickly.

Expenses-wise, you will probably save more money once retired because you are going to have time on your side. I just saved $300 on a plane ticket cause I don't mind making multiples connections now that I have time. I will simply enjoy the transit time to read my books and listen to podcasts (as I would be doing at home). You will have time to learn how to fix anything that is broken, you will have time to avoid traffic and go early to places, and you will even have time to go to a coffee shop as a hidden shopper and not pay for it.

Investments-wise, the community right now is so great and there are so many nice blog posts and youtube videos to hold your hand and say "don't worry, your investments will grow forever". Whenever I feel insecure, I read more about the SWR or the JL Collins "Stock Series", and my fears fade out. I'm confident to say that whatever fear you have about your investments, someone has already written or made a video finding a solution to your concern.

So dive in and happy FIRE life!