Idiot paint question

So me being 17 and getting a 6 for my first car, it is clear i did not have much general knowledge. I ended up tinting my tail lights perfectly, which led to me getting some night shade paint on my trunk and surrounding areas.

So me being the newbie i am, i decided to pick up some grey mazda factory spray paint from the local pepboys and try and correct my mistake. It turns out this was not the smartest thing i could have done:hammerhea:. Now im left with a trunk that is not glossy and reflective at all, and it looks like complete crap.

My question is; is there anything i can get like that clay "stuff" to put on my car or any other logical alternative to try and remove this layer of spray paint other than paying $300 at a paint shop?