No advice, but tired solidarity fist bump from me. DD, 7w, is a sleep fighter. Sleeps well at night (thank god), but can go all day with only 15 min catnaps at a time. It kills me.
So far, three days of following the Baby Whisperer advice is working. So far, touch wood, fingers crossed. The overtiredness/overstimulation was horrendous, but we've managed 13-14 hours in 24 in the past three days and she is already easier to settle. This is compared to total of seven hours in 24 we had before.
Advice I'm taking and finding helpful (not following all of it):
Try to feed about every three hours, and in between not mistake cues for hunger (she would eat every hour). Obvs not denying food, just being sure it's needed before offering. Play or change or bath after food, then settling (thought this would be impossible but surprisingly not). All feeding and settling and naps in quiet room. Blocking out light and noise (this one is probably making most difference) from nap space - I was paranoid I'd train her to need to sleep at home, trapping me for evermore, but she will nap in pram more happily now not exhausted. Not picking her up the instant she cries, seeing if she will go back off
I also think she has/had appalling wind, and once I recognised that cry (thought she was hungry!) have managed to bring up some of it, giving her better sleep and not waking her with wind.
Bad one handed typing, apols, feeding and tired as not a morning person. Good luck!
You seem to have tried everything I can think of The Only thing that occurs to me is a really early bedtime. Say six o'clock and then enjoy bathtime with the others before gettig yourself into bed I did try a physio for colic massages and it seemed to work altho in my case it was more about dairy Could you think about getting a bit of help so he doesn't have to do school run and u could have better chance of sorting naps??