Hello, I'm sorry to hear, that our browser made you (even indirectly) some troubles, can you please explain, what has exactly happened? I understand, that you've been using Chrome for a while and you wanted to try Avast Secure Browser, but I don't get the part with the data reset, did chrome reset itself for no reason? Did you try to import bookmarks from chrome to our browser before the reset?
If your bookmarks are gone and you can't find them in any browser installed, only thing I can suggest you is to stop immediately saving ANY data on your disk and try to use some file recovery program, which would scan your disk for deleted files (if a file is deleted, system just marks it location as free, but physically the data are still there. These file recovery programs scans space marked as free, if it contains some deleted data you need. As longer the data are gone, the lower chance is to be able to recover them since any new file could override the data). At my system I have found my Chrome bookmarks in this path:
C:\Users\[user]\AppData\Local\Google\Chrome\User Data\Default\Bookmarks