Fluffy, I think you need to focus on the anxiety rather than the looks. Can you spend a little bit of time each week going to something like yoga to learn to control your breathing.
Also mindfulness, which involves you acknowledging the feeling and then moving on from it. If you can't afford an actual course, there are some great books on this out there, including this one which was recommended to me when my anxiety started to grow:
www.amazon.co.uk/gp/product/B004TTHD9O?keywords=mindful&qid=1436863617&ref_=sr_1_1&sr=8-1
There are other simple things that you can do to. Can you try reducing the amount of caffeine you have per day. A couple of switches to camomile or peppermint can help.
If you can, take the time to go out for a short walk, maybe ten minutes around the block, taking time to focus on the smells you can smell, and small things like the texture of bricks in the walls, or the shine on cars - small things that will bring you back to the present when these thoughts start to get away from you.
Good luck with it. Remember, wedding jitters are usual and common, even for the most robustly mentally aware. Don't beat yourself up about them, don't attack yourself for 'ruining your wedding', just quietly accept that what is happening to you is normal and that there are ways of reducing some of the symptoms.