dig deep...with help
The benefit of the sacraments is tied in no small way to the self-examination that accompanies their partaking and/or witnessing. Sharing in the bread and (wine) necessitates an inner review; the sign of baptism is meant to cause us to reconsider our own baptisms anew. So it's worth entering into the work of self-examination with a little more structure perhaps. Introspection can easily run aground into either a very superficial consideration of self or a far too belabored, encumbering, paralyzing exercise. Jonathan Edwards preached an entire sermon on what is the nature, purpose, and manner of self-examination taking the Psalmist's request of God to "search me, O, God" (PS 139) as his starting point. It's not short and sweet but it is rich.
What has to circumscribe our exercise of self-examination is an abiding belief that is the Spirit of God who accompanies you. The Spirit does not take lightly our sin or our unwitting cherishing of it; that's why we have to be patient in the process and willing to face things that may deeply sober us (sorta like Scrooge being led about by the various ghosts to see difficult things). But we also have to remember the Spirit doesn't take us by the hand through this process and then simply cut us loose to go figure out the remedy ourselves. He is like the physician whose job it is not only to diagnose pathologies but also prescribe treatments.
It is never a waste of time to ask yourself why you do what you do. Self-examination brings that more sharply into focus. And in those moments where no explanation can be found as to what prompts those responses--those self-aggrandizing or cold-hearted habits--but the nature we have inherited from Adam (for which we remain responsible), we lay ourselves upon the Spirit's surgical table, as it were, and ask for Him to excise what we cannot (and often would not) do.
I commend to you Edward's treatise on looking inward. It's worth printing out and keeping in a safe place that you might refer back to it regularly.