It's tough to deal with, especially if you're working. I can't imagine how much that adds on to it, but at the very least, like the previous poster said, enjoy smaller pleasures. Even though it'll seem that way at times, you don't have to have legal status to enjoy everything in life, and the more one thinks that, the more one succumbs to negativity. You can still read a book, listen to music, play sports, and have friends to care for even if you don't have a green card. They help put things in perspective.

Point is, be the best person you can be, regardless of your circumstances. We're all going through tough times, and while it's easier to dwell on past oversights, it's necessary to live in the present and try to enjoy whatever you can. If you're religious, find comfort through that realm of your life. Speaking with a priest was, for me, one of the best ways to help cope and understand how to sort out things.