DSLR and HD on YouTube?

I recently filmed a short clip of my pet with my Nikon D3100 and when I uploaded it to my computer and edited it, it was in HD but after I put it on YouTube the highest resolution was 480p but the quality seemed worse than that.

Is it to do with my internet speed, it was a 2 minute video but it took 80 minutes to upload?

My download speed is 13.34mb/s which is alright but my upload speed is a bad 0.74mb/s.

Added (1). Oops, I went onto the YouTube website and just clicked upload.

You didn't mention any software name from which you uploaded that video on youtube!

If you directly uploaded it on youtube by going to youtube.com and upload then it should take the same quality in account which you are seeing in your PC.

If you are using any software then change the publishing settings of youtube to HD or 1080p before clicking on publish/upload.