Why does this keep happening to me?!?

Okay so I've been on here for like 5-6 months. I've never had any problems. Now in the last 2-3 weeks/months (I'm not totally sure), all these people keep emailing me calling me a troll and yelling at me! Like seriously what have I done? I'm 16 and [just today] I was told that I must be younger than the actual age limit & have the maturity level of a 4 year old. Why do they keep pestering me? What should I do?