u/Sensitive_Home_5150

New to posting and to woodworking here, but decided to try my hand at building a storage bench. The problem is I went with this angle at the end that has caused me endless problems. Just when I redid the frame and finally got it right, I cut my plywood front and have now realized that the angled cut is causing the edge’s face to be longer than the right angled one it’s butting up against. Any advice on how to fix this and the horrible gap? I also know that my floors aren’t completely straight and that might’ve been the first mistake.