get all the commits done by me in the last 5 days in git

Try git log --since=5.days --author=roger, assuming that roger is your username.

--author actually accepts a regular expression, so if you wanted to find either roger or rachel‘s commits, you could do git log --since=5.days --author="r(oger|achel)".

If you want to search on any branch and not just the current one, then also add --all.