I live with depression myself so I know that you can change your thoughts. Nobody ever said it was easy... but anything in life worth having is worth the hard work to get.

Feelings just are, they are neither right nor wrong and I know for a fact that many of them are induced by our thoughts. We can change our thoughts, as in the examples above. We can even take an experience and see it from a different perspective (our thoughts) and derive good from them, sometimes even happiness.