How to get rid of full screens that won't go away.

I was using my MacBook Pro with my tv through HDMI. I made a window full screen on my tv ( I was using Blender 3D software and the window on the tv was the same application I had on my screen). When I unplugged the HDMI the full screen window on my tv went onto my MacBook. The problem is that the window from the tv is now full screen on my computer, and there are no options in the tool bar to minimize it. When ever I open this file that window pops up along with the window that was on my screen. It creates lag and I need to get rid of it. I need this file. Please help!