Have you read the book recently? Is there anything in there that's jumping out at you regarding your routine?
As for the breastfeeding issues, it's often not too consistent with breast fed babies as they could take 1.5 oz at one feed and then 6oz at the next (that's an extreme example but it often differs by an ounce). Therefore, we do recommend that you use a "loose" EASY i.e. you follow the pattern i.e. eat, then activity, then sleep etc, but you ignore the clock and just follow baby's cues.
You said that sometimes he'll only feed for one minute and then not appear interested. Are you sure you're interpreting his hunger cues correctly?
I would recommend you kinda go back to basics and just really watch him for a couple of days. Ignore any ideas you've got regarding routine and just follow his lead. Babies will normally feed fairly regularly so you may find that he'll sort himself out providing he's definitely hungry when he's eating.
Have you tried breast compressions to keep him interested? This may prove helpful at night too. Do you offer the second breast, even when he's fallen asleep on the first?
I did think possibly reflux but if he seems content at the end of a feed, this seems unlikely...
It definitely sounds like a routine issue as well though...