Uncontrollable Top-Down Player Script

Hi there, I'm having a massive issue with my code as the Player script is making my sprite (box) move uncontrollably; any help would be greatly appreciated, I'll post a GIF and a couple of screenshots below:

Result:
https://gyazo.com/6cf35e8e54b0a2fdaf1e4daf1e0d76e9

Camera Script:

https://gyazo.com/d672d88c115b52e23454d38cbe8119c3

Player Script:

https://gyazo.com/196a2a23a3fb42d4d5ab0ffd53cd3f16

Many thanks!

 

Progress report, the script now works and the block follows my mouse movement however every time I start the script it seems to jump in the air

 

Do you have other objects attached to your player? Lots of time a random object having a collider is the issue.

 

I actually managed to fix it, I'll act like I know how; nothing is wrong with the code now however I would like to make the mouse movement script I added a bit less sensitive; I was planning on changing the title for random enquiries