Sunscreen later in life help

I've read all the posts about help, I am 30 and only just now wearing sunscreen. Everyone says better now than never. That's great. But then I see all these other comments saying oh I started at 8. Or 12. Which makes me feel freaked out! I am currently 25 and in my head about how I'm only now starting a sunscreen routine. I have spent 4 hrs the last 3 years outside in the morning due to work, no hat, no sunscreen, no glasses. I used to to on hikes every weekend as a kid, again, with no sunscreen. Not that I want to look young forever, but I feel like I messed up being the age I am now, and only now starting sunscreen. I have fine lines on my forehead, awful 11s (which I attribute to health issues and always hurting). But can someone truly say it's ok, and it will help, and all the damage isn't done. Idk it's just hard seeing all these people who have started it so much earlier than me, as I didnt know any better!