Backlinks de-indexed

I'm wondering if anybody at any time experienced the same thing or is going through the same thing as I am right now.

As of about a week ago, all and any indexed backlink that i had with any one of my sites are all gone.

I mean every single last one. That means ...all my bookmarked site links....rss feed links... social links....even any backlink that was out of natural occurrence is also gone ...zero.

That's 2 years of working my sites ...sites that have excellent content ...no spam ...regular postings to most and relevant linking.

The best of them were all sitting on the first page for the main keyword...some on the way there ...being on the second page.

I never made much money from them but made a little from some adsense and a couple affilate programs. Its like someone scoured my sites and killed every single backlink ..even the ones that were present for almost 2 years.

I sure wish I knew why ...they are good sites and I worked so hard to get them noticed.

If anyone could offer any suggestions or reasons why this has happened to me ...please send me your thoughts

Thanks

Bear