Breaking up is one of the hardest things to do.
I always thought that breaking up with someone would become easier each time. I used to say, "I just have to get used to it and it won't be too hard in the future". However, breaking up with a new person can be as hard as the first break up. Having a relationship involves more than just being "with" another person. At some point, you start thinking about your lives together and plan things for the future. You actually become part of each other's lives in a very profound way. Getting over a break up can be a very difficult process, and healing may take quite some time. It is possible to feel better with enough time and support. :-)
I so agree with your post! It really hits close to home, too. And it DOESN'T necessarily get better after the first partner... you're so right. Every relationship is different, and having said that, every breakup is different too. Some could end on far worse terms than others.
For example, some of my partners I have felt much deeper emotions for than others... that's just the way it works though. When I was younger, I made the mistake of making my whole life revolve around the partner I was with at the time, making the breakups detrimental. But now I'm slowly learning that I need to keep my sense of self, and that helps.
But I find the more special the bond was, the harder it's going to be. It doesn't matter how much older or wiser you are... it won't necessarily be any better than the first. You are right that it's not just about being "with" someone- there are so many strings attached, so much to consider, so many memories and emotions at stake. For me, when my current boyfriend and I broke up (and we're now back together but we had gone through a bit of a misunderstanding), it was absolutely awful. And no, it wasn't my first relationship at all... I had been through others before, and nothing about it was any easier. Why? Because we had (and still have) such a strong bond, stronger than any I've felt with anyone else. That's what made it so painful, thinking it might have been over, and what would I do from that point on.
Sorry about the huge block of text; at this point I'm just ranting... but I can really hear ya.