when i make my sigs, they are pretty good quality but after a day or 2 they drop about 50 kb's and look shitty in quality

Try a different hosting site.

i use tinypic usually. should i try photobucket or imageshack?

imgur works pretty well too.

Personally I've always used imageshack. You can actually sign up now to keep track of your uploads and stuff too. I've never had a problem with quality drops over time.

I use Imageshack and haven't had any problems like that