Boss issues

There’s a senior in my team who s not my manager but looks after the deliverables. He has been continuously targeting me n picking on me from past six months. I m not sure what has he got against me! I changed my project to escape from his insulting comments but unfortunately he is part of my current project as well..😔he continues to do the same here as well in front of my new team members. I ve lost my rating n now my mental peace n confidence as well. I ve complained to my manager but since this person is at a higher position, my manager says that I ll have to adapt to his working style. His taunts are increasing day by day n m unable to work in this environment ! What do I do?!