First Year University Inadequacy...

I'm in my first year of university studying Literature and Philosophy in a very prestigious university in England. It is a great university with a great atmosphere and has been voted  the University of the Year. The standard of academic ability is high and everyone you talk to is clever, even if they are socially inept or lack common sense! My problem is that I feel that I just do not come under the same level of intellect, I know this is probably a very common feeling. My subjects only make this worse as I can fully accept that Literature is not the hardest of subjects in contrast with let's say medicine! I have never been one of these people who can get easy A's, before A level I don't think I even thought I was remotely clever! Over A level I had to really work hard to get my grades and I got good grades and even got higher grades than the entry requirements for my course. But now that I'm here, I just cannot keep up and it is really bringing me down because I just feel completely and utterly stupid. Of course, there are some factors which help explain why I am not doing so well: last term I barely worked cos all I wanted to do was have a laugh and I also didn't go to half the lectures! But this term I have decided to be better and yet I am still struggling. Maybe I have just had bad luck with the people I hang out with, but all my course mates don't struggle at all, in fact they do all nighters and get 1st in their essays whilst I get 2-2s. I can't help but compare myself to them (I know, I shouldn't do this!) and it just adds insult to injury. In seminars I find I have nothing productive to say and therefore cannot give input into the discussions, in lectures I will not understand what is going on. Chances are others in my lectures feel the same, but it is unnerving that I am yet to encounter anyone who is struggling as I am. It is making me feel completely and utterly stupid, especially when my friends will bring up books they have all read at the pub (yes, I know, not my first choice of pub banter!) and I am just sat there, in some cases not even knowing the authors! I am studying Literature for Christ's sake! At the end of the day, they have an interest in looking through scholarly work in their spare time and I enjoy watching movies and doing **** all! I am starting to ramble, basically I feel completely inadequate in every facet of my life, especially the academic side, and it is making me seriously consider dropping out because I am just hating this feeling of never being able to hit the mark. It's embarrassing! I really don't know what to do or believe about myself, I am well and truly stuck!