Unity2D game draw arrow based on relative position to object.

Hello,

I firstly hope this is in the correct section since this is my first time posting here...

I am trying to get an arrow to draw the relative position between the player and an object. I have a single arrow image and rotate it when nessecary to show the position of an object on an image (to be changed later into the HUD). I have only recently started working in unity and i cant seem to get it to work. The function I used to rotate my arrow is bugging really bad and the result is horrible.

I am probably doing some things that are bad practice since I just started, but if anyone has an idea on how I need to approach this, it would be very much appreciated.

Code: http://pastebin.com/E7puFTjL

PS: this might be on here already but since I couldnt find it I decided to make a topic about it. if im wrong please redirect me to the page where I might find the answer.