outliers and unusual observations

Assuming that by unusual observations you mean leverage points you can asses its influence by inspecting Cook’s distance, but you should only worry about leverage points which are also outliers.

If you need more specific help please provide a minimal REPRoducible EXample (reprex) ilustrating your issue. A reprex makes it much easier for others to understand your issue and figure out how to help.

If you've never heard of a reprex before, you might want to start by reading this FAQ: