newborn "crying it out" to sleep unless held:(

i KNOW your not supose to let a newborn "cry it out" (CIO)...but i don't know what else to do...

ds is ONLY happy when being held...i hold him almost all day long, and he's quite happy like this...but at night, i've GOT to sleep - i'm returning to work in 2 weeks (ds will only be 6 weeks old) which i'm NOT happy about (but thats a whole other story) - but i've got to sleep...and i can't sleep with him in my arms...i tried this for the first 2 weeks...and i was so tired i felt drunk from only sleeping 1-3 hours per night (and even that was in 30 min. increments)...so at 2.5 weeks old i started putting him in his crib...

this resulted in his crying for 5-20 minutes before falling asleep for 60-90 minutes, then wake up, feed him, put back down to repeat the cry/sleep cycle...

i'm still only sleeping 3 or so hours a night...i wait until 12am to put him in his crib - he wakes to eat around 2am feed - back to bed by 2:30/3am and then i'm up at 4am for the day...i wait until 12am to put him down because i don't want him to CIO all night long...but by 12am i'm so tired i could fall over...

needless to say i'm SUPER tired...and probably not real functional to work, but i doubt much will change in the next 2 weeks so at least 3 hours is better than 1 hour sleep per night...

i keep reading on the interent (GOd love it) that you should NEVER let a newborn younger than 4 months old cry like this, that he will be insecure, feel unloved, and be confused...but i don't know what else to do!

we've tried a co-sleeper (in arms reach that attaches to our bed), i've tried sleeping while hold him in bed, in a chair, on the floor...i don't know what else to do...

i can't "nap" when he does because i have two other kids who aren't old enought to care for themselves (7 and 5), and well...with returning to work in 2 weeks...well there's no napping there -

i'm also breastfeeding (well mostly pumping) so sleeping while someone else feeds him/holds him is not an option - plus my dh can't sleep with him either - he does help - but dh is only getting an hour or two more sleep than me...

suggestions welcome!