I'd like you to show me the claims that the "Big Bang" says that something came from nothing. Since there were no observations done at the instant time/space started, the possibilities of what the condition of our universe was before that crucial moment will probably remain in the realm of theory and philosophy. The Big Bang is what happened to the universe AFTER things were set in motion. For all intents and purposes, however, the topic about what happened "before" time started is moot, as before is a term relative to time, which hadn't yet existed. The fact that you think this means "nothing comes from nothing" shows you're obviously not familiar with what it actually means, but knowing your particular persuasion, that's not entirely uncommon. I'm sure you've been fed a steady diet of anti-science rhetoric from your local pulpit. These concepts aren't exactly the easiest to understand and can be a bit counter-intuitive.
There are some mysteries left to the universe, of which the earliest moments are included. It is tests like the LHC that help us understand how it could have happened. Its entirely possible we won't get the results that are expected. Many turning points in scientific thought have come from these "Eureka!" moments.
For a primer on the "Big Bang", I'll suggest this to start out:
http://map.gsfc.nasa.gov/universe/bb_theory.html
Its a good primer for those not versed in the sciences.
As for your "shrinking sun" claim, all I can Google off hand are creationist sites touting it...in what journal was it published? Or do you happen to have a link to a site that cites sources?