Uploading to Youtube from iMovie stopped?

For about a month, I have been wanting to post a video to my YouTube channel from my editing app, iMovie. I have tried almost everything! I deleted iMovie and redownloaded it, I have contacted Apple Support Chat, etc. When I contacted support, it didn't really help because the tips they gave me, although the tips worked on the other people they tried, didn't work with my case. I have also tried uploading manually to YouTube, but there are so many problems with that such as the fact it takes like a day and a half to upload a 5 minute video, or that despite having a good quality video (720p-1080p/HD), the audio is degraded immensely whenever I upload manually. I love to film and edit, and it makes me sad that the situation is still not fixed, and I hope one you can help because that would be really awesome. If any of you can help me, please do so because I don't know how to fix this situation.

All in Reply,

Thank you!

By the way: My iMovie is version 10.0.9 which should be completely updated, and my computer (MacBook Air mid-2012) is version OS X Yosemite 10.10.4 which again should be updated since my computer says 'No Updates Available.'