QBI is computed separately for each activity, so for your activity with negative QBI, no QBI deduction will be computed. The negative QBI carries forward to reduce positive QBI in subsequent year, but wages and unadjusted basis numbers from 2018 do not carry forward.
If there is positive QBI from other activities in the same year, the negative QBI will be used against that positive QBI and not carried forward.
The wages from your activity can't be used in computing the QBI deduction of another activity unless the activity qualifies to be aggregated with other activities and the aggregation election is made.