Questioning Myself

Recently I have been spending a lot of time in my head and trying to determine the motivations for what I do.  It's tough to discern the true motivation for anything I do.  Where I get screwed up mentally is when I think I am doing something that seems like it would be what God would want me to do but at the same time I can see some selfish motivation behind it.  Am I really doing those things for God or is it for me?  I have recently started to struggle with an even worse possibility.  What if I am so self-centered that my thinking it is pleasing to God is simply me deluding myself into that belief?  I don't really see this as a crisis of faith so much as a crisis in discernment.  Have I drifted in my faith so much that I can no longer discern the proper path and desires?