That’s probably still way too much for your performance level. What about cutting it to 2 days of 300-400m a session (so only 600-800m a week)? Judging from the volumes you’ve had with no therapy and the resultant minimal improvement, I think you’d be best off taking some significant rest time, but that’s just my opinion.
Charlie has a 10 day taper. I am not familiar with it, but I know you can get it on DVD. I would personally reduce the calorific intake, but then I am quite obsessive in terms of diet and my weight, so if I’m expending less calories I’d be conscious I’d be taking on excess calories unless I cut back. Dave Lease used to cut the weights down significiantly in intensity. Linford used to chop them all together.