i fixed the MySQL Connection problem, writing down the solution if anybody needs like me in the future;
1-) open the terminal as root
2-) cd /etc/mysql
3-) nano my.cnf
4-) find the line bind-address = 127.0.0.1 and add # to beginning (comment it out), it should be like : #bind-address = 127.0.0.1
5-) save and exit from nano
6-) service mysql stop
7-) service mysql start
and now you can connect via network