Thinking , upset, afraid. These things?

During my childhood I am girl who was very active, brilliant and I used to win in all the competitions whatever I had participated. Running race is one of my best competitions where I used to win first or second place. I like indoor as well outdoor games. I was playful girl and used to notty But when I came to 7th std that is where I changed comptly like I have become reserved , stopped playing games and will be always very moody upset and depressed. Now I am working in company where people used to tell me that I am always thinking about something that is where even I realised yes I am thinking , I don't why , I am very sensitive person and afraid of little things. I am not behaving as if grown up girl. these days I am feeling that I am getting worst compared to previous days. could you pls help me to get rid of all these things ?   I have some personal pblm and health issues as well which is making to get upset about myself. I still have some more pblms ...