Hypothesis about productivity:
1) You're not unproductive, you just feel overwhelmed. At least, feelings about productivity are mostly disconnected from actual productivity.
2) Feeling overwhelmed reduces productivity, and worse, wipes out all positive emotional payoff from productivity.
3) You feel overwhelmed not because you're unproductive, it's because you feel responsible for additional things until you feel overwhelmed, and you do *that* because you've been raised to not value yourself.