@OP It does sound like you have a room and setup problem - see https://www.stereophile.com/content/bw-802d-loudspeaker-measurements - coupled with the fact that your amplification is not the most synergistic match for 802Ds.
BTW, apropos the post above, while B&W make a big hoo ha about being used in Abbey Road, they are not studio monitors. Having owned a pair myself for hi fi purposes - and sold them due to their inaccurate frequency response - they are a very long way down the list of speakers I would use as studio monitors.