Around 2TB/year/subnet sounds reasonable: compared to others. But yes your node thinks it’s capped at 2TB. That could be defined in your docker startup command, or your docker-compose.xml… or even your config.yaml. Check your start command first.
As for your payouts… you’re still early in your withholding period. The first three months 75% of your earnings were banked… and the fourth+fifth months 50% were banked. And then even with what’s left-over… there’s minimum payouts based on ETH fees (if you chose the ETH network: last month the minimum was $0.21). Check the “Payout Information >” link in your node UI to see how much you’ve earned so far.