Being socially awkward

My capacity for logic and intelligence in social situations is limited at best. This is why most people I speak to a)leave the conversation quickly, or b) laugh nervously and try their hardest not to make eye contact with me. I am the person who is sat alone at a table at parties. There is usually a sizable area surrounding me which is barren of people; nobody will cross into said area apart from close family and friends- people who have had the required adjustment period (and possibly therapy) and are therefore able to cope with my presence.
The fact of the matter is that nobody wants to stand and chat with the girl that just made a walrus impression by sticking two bread sticks/marker pens/party blowers/tampons up her nostrils. People are just not cool with that sort of behaviour.

They're my real tusks. Honest!

Even when I'm not doing animal impressions (by the way, you should totally see my moose impression- it's THE SHIT. You probably will think I'm a moose for at least a second.) then I'm usually creating awkward silences in conversations that, until I was invited into them, were flowing.
    Take as an example, last Christmas. It was boxing day and I was at Mr Boyfriend's Dad's house. As happens at Christmas time, there were members of extended family at the house, and with it being Mr Boyfriends family, I didn't know many of the people within the vicinity. I sat in the front room, waiting for a member of Mr Boyfriends family to speak to me so I could dazzle them with my wit and charm. When the moment of truth finally occurred and someone did come and speak to me, wit, charm and quite possibly sanity eluded me entirely. Where a normal person would happily partake in a conversation with ease, it seems that I was deemed to struggle with putting the English language into a feasible sentence.
Below is how the conversation would have gone if it involved a normal person;
Stranger: Hello there, how are you? Did you have a nice christmas?
Normal person: Oh, yes, lovely thank you, quiet, but cosy. How was yours?
Stranger: Same here really, quiet. Good drinks, good food, good company...
Normal person: Well, what more could you want?

And so the conversation would continue. With me this was not the case.

How the conversation actually went, with me involved.
Stranger: Hello, did you have a nice Christmas? It's Beth, isn't it?
Me: Yes, people normally call me that... Well... Unless I'm in trouble... Then it's Bethany. But I'm not in trouble with you... so... yes, er... you can call me Beth.
(At this point I should have answered Stranger's first question and then gone on to ask Stranger if she had a nice Christmas herself. I failed on both these points. Instead, my brain told me that grinning like a mad man was the most acceptable thing to do.)
Stranger: Ah... So, you had a nice Christmas then?
Me: Yes. I asked for a unicorn and I got a unicorn, so in my opinion; best Christmas ever.
*Awkward silence*

Oh dear.
Notice how I yet again fail to ask Stranger about her Christmas?
Notice also how I fail to share the anecdote behind the unicorn thing, thus making it look like I genuinely believe that I received a real unicorn for Christmas? 
Notice how I'm not going to share the unicorn anecdote with you, my dear followers?
Well, maybe I'll share it with you one day, but until then I advise that you lock me away with my unicorn so that I cannot further my social demise.

Hmpf...Unicorn licking. It just gets better and better.