Hi,
Can anyone help please to point out what is my mistake here and how am I able to fix it? Thank you
It could be one of the two unwrap algorithms causing the stretching on the upper lid rim. Or there's an edge that should be a seam but isn't.
If you post a download link to your .blend file I'll be happy to take a closer look. The best way to do this is by uploading your file to Dropbox, Google Drive, Mega, or equivalent file hosting service then copy + pasting the share link here.