Having problems rendering a video

I just signed up for this site because I have no other place to get information on the subject, so forgive me if this is the wrong place to post the question. But, recently I made a montage of various clips from a video game, to upload to YouTube. Everything actually went smoothly surprisingly as it was my first time using Blender. However, the rendering process is a nightmare. It did render the full 3:45 but all that shows in the file is a black screen. The audio is there, but no image. Also, I noticed that if I change my preview window proxy to anything other than 25%, the image disappears. I can’t play/preview the video unless I have 25% selected. Now that is the proxy I was using to edit each clip, however, it won’t allow me to change the proxy to anything else anymore. When I hit rebuild proxy timecode indices, the loading bar gets to 5% then quickly goes away and nothing happens. This happens on every clip. I’m not sure where to start because I’ve messed with so many settings and I spent so long on this I’d hate to see it never be able to be rendered. If anyone can offer help I’d be extremely grateful, and if you need any more information I’ll try to get that to you. Just keep in mind I’m a tech noob in general, and a first time Blender user so I apologize now if I’m hard to work with. Anyways, thanks in advance.