Problems with Premiere Pro CS6 Export Quality

Apologies if this is in the wrong area of the forum, and if I missed a similar question somewhere else, but I'm having trouble preserving the quality of videos when I export them using Premiere CS6.

Basically, I put together a quick opening for a simple 20 second video where a took a punch of png images a made in Photoshop where I have them shift position in the video for the first couple of seconds.

Then I added a short video I took with my phone camera (galaxy s7) after the opening and had it fade out. This video is intended for facebook or youtube.

Now, I'm a complete and total novice when it comes to editing, but it looked relatively okay in the editing suite itself. When I go to export it, the first several youtube presets I tried made the video bounce up and down rapidly. I'm using the H426 format, with youtube hd 1080p 29.97fps preset, which has so far given me the best quality. Though, the quality is still vastly inferior to the original phone video that was taken before I started editing. The fps of the original video clip that I imported was 29.99. I'm not entirely sure what other information might be helpful here.

Another thing that might be relevant, when the video was initially imported it was upside down for some reason. I flipped it using video effects. Could that be the cause?

Again, I apologize for my naivete when it comes to this sort of thing. This is a quasi-job related project where I told my boss I had minor editing experience in college, and as a result this project fell in my lap.