Every relationship will change those involved in some way, and change is good.  I am completely different than I was before Justin, but he didn't change me, I did.  I changed me to fit better with him, and vice versa.  People aren't changed by the other person, they can only be changed by them selves.  Make sense?  Basically, you are together because you liked each other the way you were, but you will continue to like each other through the changes, and overlook the things you might not like. 

And depression is something you have to just work on.  Figure out what makes you upset, and try to figure out a way to keep that from happening.  Try looking on the bright side of everything, and maybe you will start to see things aren't so bad.  I don't know if you know much about my battle with depression/anxiety, but I have done a pretty good job conquering it myself, and I am much happier.  Doctors put me on pills, and they made me feel horrible.  I wasn't sad anymore, but I was never happy either.  If you need to talk, you know where to find me.  Just don't let anyone go over a fight.  Fights make you stronger in your relationships.  Believe me, we have had many!