If you've done very little editing or metadata work (keywords, titles, captions, ratings, putting images in collecitons, etc.) before your troubles, then starting over again may be a resonable thing to do. However, that is usually not the case and most folks would take a dim view of having to either abandon a ton of older images or have to re-do all that work. It's sad that "several people" were not able to get you back on track as your situaiton, at least on the surface, does not seem all that complicated to get fixed. Were these LrC experts or just random relatives or friends?
As long as you have your old catalogs (or backups of your old catalogs) and the image files on disk - both of which you say you have - getting the images re-linked in LrC should be your first option. Unless you did a load of folder renaming and/or moving outside of Lightroom this should not be hard to do. Of course some situations are more complex but in most cases they are not. So, getting your old catalog up and working should be your first choice.
However, if you are resolute that you want to toss all your prior work and start over, start up LrC but if it either says it can't find your catalog or it wants to update a catalog, pick the option to create a new catalog. If you get stuck send us a screen shot of how far you get and we'll tell you what to do from there. Once you get LrC open with a new empty catalog you can start importing images (either new ones or old ones). However, if you import old ones they will not have any of the LR work you did on them in the past unless you had "automatically save XMP data to files" turned on in the past which is not the default so it is unlikely you had that turned on. But, be warned. Once you import older images and start doing stuff with them you are pretty much cutting off the option of recovering prior work you did in the past on those same images.