Two things....
1. Backgrounds can be tough... but I don't think every panel needs to have a background. In my comic, I choose to sometimes omit the background, and when done right, it enhances the story. Many mangas successful use this "technique".
2. I came up with a helpful trick for doing backgrounds using a free program called Sweet Home 3D. This trick requires a time commitment, but it's worth it if your comic takes place inside the same house/building for many pages. I used the software to create a 3D image of the building/house that exists in the story. You can also add furniture. Once completed, the software allows you to visually "walk through" your structure. You can adjust the view to get any viewpoint/angle you want! So just get the view you want for the background, and copy it. Bam! No measuring, dealing with vanishing points, perspective points, etc. Of course, as a comic artist, I personally believe you should know how to draw backgrounds realistically. But this trick can save a lot of time and yield some dead on and perspectively sound backgrounds!