Engaged, getting married soon.. Help

I am engaged and we're getting married in January 2015. Our wedding will probably have 300+ people present... And to be honest this is never what I wanted. I wanted a smaller wedding that was done quickly. I don't like long engagements and thinking about how many people will be at our wedding literally makes me sick. I have anxiety and suffer from panic attacks and this is freaking me out. I just want to be married, I don't want a large wedding that is costing me a ton (which it is).