I've been running for 36 years (obviously I'm a masters runner) - almost all of it competitively. I also find Daniels' I pace to be quite difficult.
Therefore, if I MUST time my workouts, I use my 5k "pace" as my guide, not the quicker 3k "I" pace.
About half the time, I simply do the prescribed time (i.e. 3:10 = 5k pace for 800) and run it off the track (I prefer grass). The other times when I think I need to get a reality check and I go to the track, I really try to concentrate on remembering if what I'm running feels like "5k effort" - i.e. can I hold this pace/effort for a whole 3.1 mile race? Most of the time, I am pleasantly surprised that my perceived effort very closely matches my actual 5k performances. It's nice to check at the end of an interval and see "ah ha! that's right where it should be!"
Also, it makes the workout a little less intimidating to keep in mind that it's my race pace for 5k since I SHOULD be able to run that pace for a 1k or 800 or whatever.
The other thing I find is that by nature, VO2max pace or 5k pace, or worse, R pace is comparably tougher for me to feel comfortable running. I run a fair amount of mileage (aiming for high 60s/low 70s) and really have no issues with long runs, but (unlike you) struggle at the fast end. What I'm gradually coming to realize is that 1) I really DO need to keep those faster sessions in my training, despite hating them but 2) perhaps I need to take a bit more recovery between sessions (not doing them once a week, but maybe 2 times in a 3 week span) until it isn't quite as stressful.
Finally, in my hurry to "get the damn thing over with", I often skip stretching and other warmup (other than a 2-3 mi jog) and this is a BAD idea. Besides the injury potential, it makes it a lot harder to launch into the right pace. I should do some dynamic stretching as I have heard this helps a lot, but I do now do a 800 or so at tempo effort prior to starting to do intervals. I find that it actually makes switching to faster running much easier. (I also tend to get faster with each interval as my body continues to loosen up and I relax).