Is it normal to look younger the older you get?

I feel like the older I am getting, the younger I am looking. Im in my early twenties but I look like a 16 year old yet when I was 18, people thought I was 25 and I see it in pictures. Ill see pics then and I think I look about the same as right now but when I see pics of me now, I do look like a baby. This is not fun. Everyone says youll be thankful later and I know but right now I wish I looked older or at least my age. Plus my voice doesn't help either. I think I sound like a little girl. It bugs me the most cause people dont take seriously especially in jobs and it affects me. It's like I naturally conform to being looked at as a child so I end up acting like a child and that doesn't help my case at all. However, I have heard also that once pple get to know me, a sense of maturity comes out and then they believe I am my age. But that happens a little. Sigh, idk what to do? Put more make up on? Dress differently? I dont put too much make up and I dont dress girly, in fact, I usually wear workout clothes but when I have to dress formal, I look girly yet sometimes someone will surprise me and say "you go to high school?" Im like uhhh no I graduated college already!