HUGE Position drop because of Backlink's URL change?

Hi,

I will try to explain my situation here the best i can, maybe some of you similar with it and know how to help.
So for the last year i had a keyword SERP between #1 ~ #3 steady. Recently it dropped to #22 for the first time in one year
The only significant thing that happened recently was the following:
450 Quality links were build over half a year through some system and all of them with the anchor pointing to http://website.com/smthng.
now on the Search the result was http://website.com/ not http://website.com/smthng for that Keyword.
so by mistake or something this Backlink service changed all the 450 links from http://website.com/smthng to http://website.com/
and after few days this happened. How can i resolve this? Will changing all the links back to /smthng will help? is it not the reason for the drop?

Any help is appreciated! Thanks.

So essentially you have build 450 links to the homepage in a short time period. It could be a penalty or a dance. Just wait and watch is all we could say for now.

mariejohns said:

So essentially you have build 450 links to the homepage in a short time period. It could be a penalty or a dance. Just wait and watch is all we could say for now.

Click to expand...

Those links were build to the http://website.com/smthng and in 1 day all changed to http://website.com the Domain is 10+ years old and contains over 5300 links.