Photobucket and other similar services may possibly reduce picture quality for less bandwidth, who knows? OTOH if you took the pics with your phone and haven't reduced the file size, they are of quite poor quality to start with. The original should usually be the largest but in your case the edited ones are four times the size of the original. Also 372px × 662px is a very small and inaccurate photo compared to the 4000 x 3000, 3 Mb pictures of my Canon PowerShot which still is only mediocre as a camera. You simply don't have much to work with.
If you can, add the image quality to the maximum. Work with the best quality original until you're happy with the result. You then can use some tool to shrink the photo for fast online viewing.