Thank you for all your responses, they are very helpful. I have a couple updates that may shed more light. My best friends don't like him that much. Before we started dating, we all hung out as a group and it was fine, but after, he started paying so much attention to me and being so affectionate, that they felt like they were being forced to go on our dates. My bf, meanwhile, told me he felt like he was being invited into our friend circle and didn't realize they felt he showed no further interest in getting to know them. I understand both sides, but it's caused a lot of issues in the 6 mos. we've been together. My friends think he's presumptuous and doesn't read the atmospheres of groups well to figure out what the appropriate boundaries are. They think I try harder to understand him than he does me. And I'm not totally sure how to feel about that. He didn't realize he was bothering my friends so much until a few little arguments went down online and they deleted him off of facebook (oh no! I shouldn't laugh, but facebook man...). The next day I met up with him and his mood was unlike anything I'd seen before. Just very sad in the eyes. He immediately arranged to meet face-to-face with my friends, and yesterday they had a talk and heard each others' sides. Hopefully things will improve. I don't know why I mention this incident - I guess I feel it is very indicative of his character. He wants to be liked, and it's crushing to him when he thinks he is but finds out he's been oblivious to the truth.
Thanks for the great response. Intuitively, I feel like you're right on with your assessment of his behavior. All I want to do is learn to understand him so I can appreciate and accept him. I feel like I'm on the right road. I guess in many ways I can relate to him, and that is why I feel so drawn to understanding him. I feel like many of his negative traits line up with mine, and that's part of why it can be so hard to watch him when he's acting a certain way, because it feels like a mirror being held up. I can vacillate between narcissistic tendencies and low self-esteem - the difference between him and I is that I've learned to keep the narcissistic upswings under wraps, because it's not a good thing to let out and believe in.
I thought for a bit that ENTP was a good assessment, but after 3 years of vacillating about my type, I'm positive I'm an ENTP, and when I compare the two of us? The more I get to know him, the more I see how emotionally driven he is in comparison to me. We definitely link up on high Ne and low Si, which makes us look superficially similar because we perceive things in similar ways to the point where we finish each others' sentences or say the same thing at the same time (we did this even before we started spending a lot of time together as a couple). Despite this superficial similarity, I feel like we draw conclusions on our perceptions very differently. He typically reacts to things based off how they make him feel personally. When my friend was telling him some of the things that bothered her about him over the internet a long time ago, I read the conversation thinking that what she said didn't sound harsh at all, but they way he made it sound, I'd thought she had ripped him to pieces (she's ESFJ). I feel like this tendency is indicative of Fi, correct me if I'm wrong. He also has strong Te, so I figure that's why I used to think he was an ENTJ. He can get really high off of being in charge of organizing something (something that has to do with his values - with him it's environmentalism).
So I feel I've given a lot of thought to the ENFP moniker (I posted a couple threads about it here too, I think), but feel free to give any feedback.
Our age has to be a central issue, and that is something I forgot to mention. I'm 21, he's 19 (20 in the fall). We are indeed young, but I feel we are atypical for our age in many regards.
Sorry for the longest post ever. Feedback greatly appreciated!