I think that all babies are different. Fortunately, I didn't have sleep problems with my 3 girls, but my sister to this day (hers are now 16yr and 12yr) go to sleep superlate.
I don't agree with putting them on a strict schedule, waking and sleeping, the babies are usually up for a reason--be it hunger, needing a change or needing comfort. Keep on trying to put the baby down at whatever time you deem appropriate and eventually he will sleep through the night for you.
I know how hard it is when you are the primary caregiver. I have a 4yr, 2yr and 8 month old and my hubby is gone most of the time (military), so I can really feel it when I don't get enough sleep. My only other suggestions about sleep is for you to sleep when the baby sleeps. If he goes down for an hour in the afternoon, you should take a nap also. The laundry and dishes will still be there when you wake up!