I feel really down sometimes and get sad over small things. My best friend and my brother are getting closer as friends, and I feel jealous when they spend time together. I’m upset with my friend, like she’s cheating on me. It’s making me feel depressed. Then I start hating myself for feeling this way because it’s not like me. I really love my best friend; she’s the only one close to me right now, but my brother is taking her from me. They call each other and spend time together, which annoys me and takes my peace away. What should I do?