Any work you do in Lightroom is in the catalog. It is impossible to use Lightroom without a catalog.
In addition, your photos are filed in a specific location, which is determined when you import the photos (this may be a location you have specified or it may be the default location chosen by Lightroom).
So ... unless you specifically choose to delete your photos, your photos have not been deleted. To find them, open Lightroom and select File->Open Recent and select each catalog shown there until you find the one with your 170 photos.
And now ... a word to the wise: as gvb279 and Keith said, you absolutely need to stop doing whatever it is you are doing and learn the basics of Lightroom. You are clearly in need of such basic understanding. In addition to the links given above, there are many valuable instructional tutorials here: Getting Started with Adobe Photoshop Lightroom 5 | Adobe TV
Please do yourself a favor and start learning