I have a feature branch, and a master branch.
Master branch has evolved and I mean to have those updates to diverging as little as possible from master branch.
S
The have 27 and 2 different commits each is telling you that you now have 27 new commits from master and 2 new commits in your branch that are not present in origin/.
Because origin/ has been massively changed by the rebase, it no longer has a common base with origin/. Therefore, you don't want to then pull the changes from origin/ after the rebase, because, as you see, all H*** breaks loose.
If you know there are changes in origin/ that you need in your local branch, then pull those before you rebase.
If you are sure no one has changed origin/ since your last push (a safe bet if this is your own feature branch), you can use push --force to put them into sync again. Then origin/ will again have the same base as your local branch and that base will contain all the latest master changes.