CIO is not the answer. A serious talking to for youe DH is!! He needs to be more supportive and less demanding. He may be going to work etc but you spend your time doing the most important, mot demanding job in the world, raising his son!!
Carry on co-sleeping and nurse him on demand, and perhaps try reading "Three in a Bed" by Deborah Jackson. It will help you to see that you are not a failure and that your son is behaving quite normally.
We tried to go the "conventional western" route with DD1, cot,seperate room etc, it was a disaster. I read 3 in a bed, and the Continuum Concept and had an epiphany, we stopped trying to "train" our baby (18 months old by this time, and still waking every 2-3 hours a night, only going back to sleep on the boob) and allowed her to sleep in with us after her first waking (about midnight). Suddenly we all got more sleep, she became less stressed and clingy and within 6 months was sleeping all night in her room in her own bed, shortly afer this DD2 was concieved...... if you see what I mean.
What I'm saying is, change your expectations, not your mothering. Get your DH to behave like an adult and not a stroppy child, and stop thinking you are a failure. You are not.
Also, sleep when he's napping in the day, take him into your bed and zizz together, and consider carrying him in a sling during the day if he's grumpy.
Chin up, it'll get better I promise.