Inserts through Stored Procedure 6 time slower than direct insert
Make your code simple. Do not create dynamic query for simple one table insertion. for example:

create proc [dbo].usp_Add&lt;Your table&gt; List of Parameters--, datatype similar to table columns
AS 
BEGIN
SET NOCOUNT ON
INSERT INTO &lt;MY TABLE&gt; (LIST OF COLUMNS) SELECT @Parameter1, @Parameter2
--OR
INSERT INTO &lt;MY TABLE&gt; (LIST OF COLUMNS) values(@Parameter1, @Parameter2)

END