We don't solve homework and exercise problems on this site. So I will only give you guidance.
You are going about it in the wrong way. You can't determine the tension in the string the way you are doing. It assumes the string supports the entire load, when it doesn't. There is also the horizontal and vertical components of the reaction of the vertical support at the pin.
Do a free body diagram on the bar. The pivot has no moment resistance (resistance to torque). Take the sum of the moments about the pivot and set equal to zero. That will let you calculate the tension in the string.
Then take the sum of the horizontal and vertical forces on the bar, which should include the contributions of the horizontal and vertical component of the tension force as well as the horizontal and vertical reactions at the pivot and as well as the weights and set them to zero. You can now calculate the reactions at the pivot.
Good luck and hope this helps.