I'm not really sure

I have a friend who has deemed me "negative". This person is toxically positive btw. Like whenever it comes to other people it is all about whether they are thinking negative thoughts then negative things happen to them but, this person won't actually use that for themselves. I'm actually just extremely sensitive. I have always been and it's hard for me to deal with issues the way everyone else does. I need to talk about it and understand why it's happening and if I'm in the right for feeling the way I feel. They also say I should just be myself but, if I'm a sensitive person would I not be myself by being something that caters to what they want?