Why have I been feeling so anxious and sad the last 2 weeks?

Last year around November-December was real stressful... I went to my first funeral for my grandma (whom I really miss and love) and numerous other changes. I'm nervous that I'm never going to be myself again and that everyone thinks I'm crazy for being so emotional these past 2 weeks. I'm so sensitive to the news and to deaths. Why am I feeling this later on instead of right after everything? I'm only 16 years old and I want to stop thinking so negatively. I'd appreciate some positive feedback, thanks so much.