I've been growing my first mint plant for a few months and recently, some of the leaves have been turning yellow with brown spots and falling off. Parts of the plant are still unaffected. http://i66.tinypic.com/2wp01fr.jpg

Possible reasons are:
I've found these white bugs on the under some affected leaves. I think they might be aphids. http://i68.tinypic.com/345ehqs.jpg

There also some dark spots one one of the stems. http://i66.tinypic.com/jpv63b.jpg

There was also a spider building a web between some of the stems, but I already blew it off and it didn't seem to be feeding off the plant.

Please help me identify what the problem is and what I should do to help my mint plant become healthier. Thank you!

p.s sorry for the terrible image hosting website