Is it bad that we're (Me 17M Gf 17F) going this fast when we want to be each other's last?

To give some context on my relationship, we are both in the last year of highschool, we've known each other since I was 14 and she was 15 (she's 11 months older). She's the only girl I've had a crush on, the only one I've loved, she's literally the first everything for me.

I started liking her 2 years ago (and she started liking me a year ago) we were very close friends btw, and it took 1 year and 9 months for us to be together. I went crazy over her, really crazy. She's the only one who has been on my mind ever since I started liking her.

I know everything about her, everything. There's no one who knows her as much as I do. She tells me everything. The same applies to her, she knows eveything about me.

We are extremely similar in most things, we like the same music, have similar political views, like similar movies, have similar views about life. I feel like we are made for each other.

We've already talked about everything that happened to us in life and what we want in the future. One thing we both want is to give everything we have for this relationship to work, we want to be together til death do us part. I also know her family and she knows mine.

I know we are both very immature and since we are each other's first partner, we don't know a lot of things. But I feel like we communicate really well with each other, when I (or her) think that something that happened shouldn't have been that way we talk about it, we know how to see that we've done something wrong, we know how to apologise and the last thing we want is to hurt each other. We know things are not going to be as perfect as they are now, but we also know that's when we are going to really to love, to love even when thigns are not the best.

I'm also very insecure, ugly (and short, I'm the same height as her, 5'2" and I've always been bullied because of it) and afraid I can hurt her with these thoughts because I talk about it a lot. I always talk about it with her, she understands me, she knows that this is a problem (and so do I), she helps me with it, she doesn't ignore it. She is also kind of insecure (not as much as me though), and I have no problem to listen to her, to try and help her. I think this is very good for us. We get closer, we see what's wrong with each other and try to get better together.

When I think of my future, I think of myself with her, I can't really think of a future where she isn't there.

Recently (like a week ago) I told her that I get hard whenever I even touch her hand. She said there was no problem, that I shouldn't be embarrassed about it. We started talking about it and it led to me talking about her breasts and ass (btw, I never looked at them before we were boyfriend and girlfriend) and she said it was completely fine for me to look at them and to touch them. So I did that, I touched them, a lot, yesterday when we saw each other. I felt embarrassed and afraid that this was wrong, or that we were going too fast. I also sent her some pics to her of my body (chest and abs, although I am really skinny, she liked it) and today she sent me pictures of her breast, I really liked it. But I also got very anxious, nervous, excited and my breathing got heavy, my heart started beating really fast.

I also got really surprised that this all happened this fast because it took us 3 days to hold hands and hug for the first time and 3 weeks of dating to kiss, and only less than 3 months for her to send that type of pic and for me to touch her parts.

I told her all of these things, that we should maybe slow all of this down (but that I also really liked doing this), she said that she didn't see it as a problem but if I wanted it to slow down, she was fine with it too.

Btw, to be clear it's been 2 years and 8 months since we know each other (and have been close friends), I've liked her for 1 year and 9 months before we started dating and it's been around 3 months that we started dating.

Is this too fast?? What can I do to make this relationship last?? Is acting like this while dating for 3 months bad for long term success?? I really love her, I want my future to be with her, I don't want anybody else, I know I'm not going to miss out on anything, because I only need her.