Urgent social Help needed please!

Hi!
Well I think before I start answering your questions I should say that if you go to this event with the mentality that it's going to be very socially stressful for you then it's likely to be even worse than what you think it will be! I know it's hard to change this, I am a person who gets socially exhausted after a long time of being around people and not getting to be alone, but sometimes being around people can be very socially rewarding once you get past what you think they're thinking about you! 95% of the time the person you're worried is thinking something bad about you is worrying about themselves as much as you are! Anyway back to the questions at hand:
1) Becoming less socially awkward and more comfortable doesn't happen overnight, I'm sure you already know that. But there are certain things that you can do to prepare. I think one of your goals should be to have self acceptance that that is the way you are and the way you eat and everything that you're worried about just makes you a part of you and you should be proud of that because I'm sure you are a fab person and have nothing to worry about! So yeah, my tips for on the night would be making sure firstly that you feel happy with the way you look because then you'll automatically feel more comfortable. Spend some time in the days leading up to the event experimenting with your clothes and hair etc and work out what works best for you. Next, practice your posture in a mirror. Sounds crazy but trust me a better posture makes you look a million times better and subconsciously gives you confidence! Focus on pulling the shoulders back and puffing the chest out but not so much that you're looking to shove it in people's faces, enough so that its comfortable to stand and walk around like! You will feel like a boss, I'm speaking from personal experience it also gives you the air of confidence without seeming arrogant I think the thing about eating is pretty tricky and I used to be nervous about eating around people until I realised how little I thought about how much or how other people were eating! If you're worried about eating messily, cut your food up smaller into bites you will definitely be able to fit into your mouth or always have your hand and napkin handy to cover or clear up any mess politely and nicely
2) Honestly, the best way to politely decline alcoholic drinks is to just say 'no thanks I'm alright for the moment'! If you feel it's not a good enough excuse then if you drive, say you're driving tonight so you can't or say you have to be up very early the next morning to go somewhere or something, so don't want a hangover! If someone forces you to have a drink then you could accept then visit the loo shortly after, pour some of it away and dilute it with water so that you don't get drunk so quickly but you look like you're still drinking an alcoholic drink if some person (who would be a truly awful person if they did) is giving you a hard time about not drinking. While I'm on the point about the loo, if you're feeling close to a panic attack or just need a break socially for a few mins then go to the loo, as everyone will be drinking they won't notice the amount of times you go! Locking yourself in a cubicle for a few minutes and breathing deeply can really help

I hope this has helped you slightly, if you have any questions or anything I am more than happy to help if not then I hope your event goes well and you have a great time