1. 200 Users for a website hosted on a sound server with proper resources and RAM, will not cause any problem
2. As initially I told you that must close the existing connections,
Simple example would be Open connection very late, Close Connection early. Example
con.Open();
cmd.ExecuteNonQuery();
con.Close();
Thus the above makes your connection available easily.
For time being this will make your website work and if you need to enhance further you can look through the steps from Mr. Hirapara