somehow it seems, LR imported every single image on my hard drive including screenshot ancient vacation pictures and web images. I checked and it doesnt seem I have auto add on how is this possible? and can I do anything about it other than delete cataloge
If you are using Lightroom, that's what it is supposed to do. If you are using Lightroom Classic, that should not happen. So which software are you using? Go to Help->System Info and tell us what the first 5 lines say.
I don't know why it did what it did. But you can go to the library module and highlight the folders that you don't want included and press the delete key. You will be given the option to delete from disk or to remove from Lightroom. It's probably going to be tedious, but if you don't want to start over with a new catalog it IS possible.