CREATE DATABASE Permission Denied In Database 'master'. Error

got rid of my error about user login rights, it was all working yesterday. but for some reason i now get this error

  CREATE DATABASE permission denied in database 'master'.
An attempt to attach an auto-named database for file C:InetpubwwwrootsqlSiteApp_DatasiteDB.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: CREATE DATABASE permission denied in database 'master'.
An attempt to attach an auto-named database for file C:InetpubwwwrootsqlSiteApp_DatasiteDB.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[SqlException (0x80131904): CREATE DATABASE permission denied in database 'master'.
An attempt to attach an auto-named database for file C:InetpubwwwrootsqlSiteApp_DatasiteDB.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.]
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +734995
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +188
System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +1838
System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK) +33
System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +628
System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +170
System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +359
System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +28
System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +424
System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +66
System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +496
System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +82
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +105
System.Data.SqlClient.SqlConnection.Open() +111
System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) +121
System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) +137
System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, String srcTable) +83
System.Web.UI.WebControls.SqlDataSourceView.ExecuteSelect(DataSourceSelectArguments arguments) +1770
System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) +17
System.Web.UI.WebControls.DataBoundControl.PerformSelect() +149
System.Web.UI.WebControls.BaseDataBoundControl.DataBind() +70
System.Web.UI.WebControls.GridView.DataBind() +4
System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound() +82
System.Web.UI.WebControls.CompositeDataBoundControl.CreateChildControls() +69
System.Web.UI.Control.EnsureChildControls() +87
System.Web.UI.Control.PreRenderRecursiveInternal() +41
System.Web.UI.Control.PreRenderRecursiveInternal() +161
System.Web.UI.Control.PreRenderRecursiveInternal() +161
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1360

  i have this in my web.config file

    <connectionStrings>
        <add name="ConnectionStringTest" connectionString="Data Source=.SQLEXPRESS;AttachDbFilename=C:InetpubwwwrootsqlSiteApp_DatasiteDB.mdf;Integrated Security=SSPI;Connect Timeout=30;User Instance=False"
            providerName="System.Data.SqlClient" />
    </connectionStrings>
    <appSettings />
    
    <system.web>
        <!--
            Set compilation debug="true" to insert debugging symbols into the compiled page.
            Because this affects performance, set this value to true only during development.
        -->
      <compilation debug="true" />
      <identity impersonate="true"/>
 and my asp connection string is
 
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionStringTest %>"
            SelectCommand="SELECT [entryID], [compID], [emailAddy], [answer] FROM [entry]"></asp:SqlDataSource>

 if i set user instance to true i get a user permission error.
 
it says on sql server management that i have dbo rights on my database, but it wont let me put datareader or write on this login. any ideas? its driving me insane