I wish you luck in your relationship but I'd like to say I come from an interesting point of view.
I am 37 but at one time I was that 16 year old girl who was dating a 25 year old guy. I knew it all let me tell you! I ended up married 6 months before I gave birth to our first child when I was 18. I was crazily in love.
The years wore on, we had a second child. I didnt know it in my early 20's but I wasnt happy. I know that sounds crazy but its true. I felt as though I had to grow up so fast and being a wife & mom I wasnt able to form my own identity. Dont get me wrong, being a mom was the best thing that ever happened to me even if it did happen sooner than it should've but thats not my point here. (and I realize you aren't driving to the wedding chapel or picking out names yet but we didnt either at first, be careful!)`
At 28 I left him. It took me years afterwards to find "me". Its not the age difference that is a possible detriment, it is the stage in life. I know you said you are "younger" than your age, but what happens in 5 years (if you are still a couple) and she is maturing?
I think the key to you 2 being able to make it is taking it slow which it sounds like you're trying to do. Trust me, do not "smother" her and try to control her. Let her feel free to mature and be who she wants to be in the next few years. Communicate, LET her communicate with you.
I am remarried now to a guy 9 years older than me. We met when we both knew who we were, so to speak. There is NO way a 17 year old knows herself yet, or what she wants out of life, or who she wants to spend the rest of her life with. Oh let me tell you she will tell you she knows, I did too, but she doesnt have a clue to how much she will change over the next 10 years.
Good luck to the both of you! You really sound like you know how to articulate what you feel which can be rare and that is a huge plus.
I hope i didnt get too "deep" just trying to give you another point of view. I do wish you luck!! Just dont let your heart (or any other part of your body

) lead you down a road that doesnt feel right, trust your instincts.