Find a new friend.
A friend should not make you feel this way.
I went through something like this too, I met my "friend" in elementary so I felt compelled to forgive her repeatedly. When she would say she was smarter than me, or prettier than me, or more popular than me I would be upset but always just let it go. One day, However, I was tutoring in math & my teacher told me I was the best tutor he had. I realized I wasn't stupid & I didn't deserve to be called stupid so I stopped hanging out with her. A year or so later she set up an elaborate plot to get someone to PHYSICALLY fight me by lying to them.
I cut her out of my life for good that day, blocked her on everything. looking back I can tell you its her self esteem that had issues, not me. Getting her out of my life was single handily the best thing I did in high school. That negativity hurts you more than you realize until it's gone.