Discriminated by senior researcher because of my ethnicity
In the comments you mentioned that getting an ombudsperson involved was not an option for you. However, your advisor does not necessarily need to know that you talked to the ombudsperson. Ombudspersons are often required to keep discussions confidential unless you explicitly tell them otherwise. You of course need to check that before with your ombudsperson before you go that route. Just discussing your options face to face with another person who has to treat that discussion confidentially is probably of enough value in and of itself. And maybe (s)he can do even more.