Is it normal for my fiancé to act like this?

So the thing is that I've been in a long-distance relationship with this guy that I've known over 3 years. Our relationship has lasted over 2 years and we're actually engaged because we wanted to have a substantial way to entwine our lives together even though we aren't together physically for most of the time (only a couple times in a year). We both believe that we have found our soulmate and our relationship works so well when we are together but when we are apart and have to talk on the computer it doesn't work, the communication seems to have got worse during the years.
Anyway, there is this thing that keeps bothering me and I would like to get new aspects to it. My fiancé is the most loving person in real life but on the computer he isn't. (Which I actually understand because I can't be much either, it feels so cold and distant somehow). But basically what I've been thinking is that if it's normal for him to "neglect" me. And by neglecting I mean not telling about me to his friends and family. To them I am a good friend of his. Only a few of them know and he says he wants to share that information only with his closest ones. To new random people he always introduces me as his friend. On one hand I understand because it could be a cultural thing (he lives in Spain) but on the other hand I'm thinking "So what? all my friends and family know it too and they might think I'm weird but I don't care." He comes from a small town and he's afraid of being looked down on for having a long-distance GF.
And I wish it was just this but it isn't. And now don't get me wrong, I definitely don't think that facebook defines one's life and means everything but now thinking about that he doesn't seem to be ok with making people know who I am it makes me wonder why, if he says he doesn't think facebook is important or anything, his relationship status hasn't been open for people to read for a while and he uses facebook to like other girls' pictures and comment on them (he's even had a conversation in this girl's picture where she is at a beach wearing bikinis and my boyfriend's trying to assure her that she's damn hot.. we were together already by then but I didn't have facebook at that time and found it later), wishing them a happy birthday etc and to me, well, not so much. I mean, he did call me on my bday and I was very happy for that but I was still wondering why didn't he want to show OTHER people that he did so. I know this might sound silly but I don't mean to focus on little details here, more like the overall image. He knows I feel insecure about my position (will tell you soon why) and yet he makes no effort to make me feel better about it. When I asked him about this on my birthday he got mad at me and started playing a game with a friend of his so we couldn't talk even though I would have loved to.
And now more (seriously sorry for the long post!): the reason why I feel so insecure is because he is surrounded by girls (and I know it's silly and I know it's not good to be jealous so I try to keep that side of me as hidden as possible but sometimes I do have to say something); his whole university is full of girls, he shares an apartment with girls, there have been girls having a crush on him, begging him for sex (one that he is actually living with now), he's had sleepovers with girls... He once overlooked my worrying about this girl that he met on the internet. I did not like this girl as she by weird coincidence was from my city and seemed like a bitch and I begged him not to meet this girl (haha ok ok jealous me but anyhow) and he said "I won't" and well, later that year that girl moved to his city for a while and they did meet and to me he said "Well I didn't actually promise you anything." The girl also gave me a lecture about how I should behave myself and how she can actually be with boys without being a huge slut (but I actually know that she's cheated on her boyfriend). We had a huge fight over that and he said he wouldn't meet her anymore but later I found out that he did and he had lied to me about it. And as if that hadn't been enough, he continued being on the internet and searching for girls from my country (it's the country of his dreams and he'd like to move here someday) or at least being on the computer and very randomly finding girls from here that he says are "very very nice" (as if he was that lucky all the time). He actually met a girl on a train that was staring at him all the time and he decided to go talk to her and ask for her facebook and then he started talking about that to me and he said it was the best feeling he had ever got and how it was such an ego booster. When I got mad he got mad at ME for being mad for making friends.
I am so sorry for the long post but I need opinions! One more thing: I actually don't believe my boyfriend would cheat on me but this position that I'm in gives me a hard time and no matter how much I've tried to make him understand I just get him mad when I talk. Am I crazy? Is this normal? Is it ok for him to do that, am I just overly jealous or are you guys thinking too that it's not normal for him to do that? Even though the post is quite long these weren't the only things that have happened but I can't make it all fit here.
Please, help me a little :S