I am married to my husband for 4 years now and we went through the same thing. I never felt "good enough" to be around his family and friends because I was not as outgoing or accomplished as they were. It bothered me a lot. I am stil suferring from it a little now so I don't want you to go through the same thing. Your relationship is still new so you have time to get it under control.
You are a unique person. There is only ONE you whoever that is. YOU are the way you are and you don't need to change for anyone because it will only make you nuts trying to impress everyone else. Highlight and focus on your positive qualities and you will realize you are just as worthy as everyone else. Just be comfortable with yourself. Your boyfriend obviously likes you a lot otherwise he would not be with you, right? So I am SURE he does not think of you as "dull" at all.
No need to discuss this issue with him because it might just make matters worse. My husband says that now he cannot enjoy either because he is always worried about me and if I am having a good time. I think it is better if you just deal with this on your own. I wish I would have kept my feelings to myself now. You should just build your confidence and self-esteem, take up some hobbies or pursue new things that you like.
Everyone, no matter WHO they are, are always conscious of themselves all the time too so they hardly ever notice anyone else's discomfort in situations. People who are loud are only covering up their own insecurities too. There was a quote from some famous person I remember that goes something like "When I walk into a room full of people, I don't think 'will they like me?', I think,'will I
like them?'" It makes sense. Even confident outgoing people are concerned about impressing others. So at the party next time try to consciously be aware of their efforts to impress and you will probably smile about it.
I have realized that people will mingle with you only if you make the effort to mingle with them. If I go to a party and just sit in one place the whole night, no one comes over to me especially if I don't know them too well. But if I go around the room and start or join in conversations or get involved in what they are doing then I will get along better with others AND I myself enjoy more. Of course it will probably be awkwardand hard at first but then it will get better and better and soon presto you are fitting in the group. Believe me this works-I know through trial and error! Isn't this what outgoing people do? They just do things without letting their self-consciousness control them, right? They are self-conscious but it doesn't overwhelm them.
I hope this LONG post helped a little. I just wanted to write because I just don't wish anyone else to feel the way I did.