Hi L.,
The sleep stuff is SO challenging. I remember the days of 20-30 minute naps. I got pretty close to completely losing it from being so tired myself and from knowing that my little guy needed more sleep but just couldn't seem to get it. But it does get better, a lot better, I promise.
One thing that helped us was to shorten our little guy's awake periods. The two-hour rule is a reasonable place to start, but as the other mama mentioned, your little guy might need to go back to sleep after just an hour and a half--or even just an hour--of wakefulness. It's so surprising how quickly they can be ready to go back to sleep at this age. Apparently, once they're rubbing their eyes, they are already overtired, so if you can catch an earlier drowsy sign (a yawn, zoning out, yanking on the ear, . . .), you'll have better luck. Another option would be to notice how long he's awake before he starts rubbing his eyes, and the next time try putting him down before that amount of time is up (e.g., if he starts rubbing his eyes after being up for an hour and 45 min, try putting him down when he's been up for an hour and a half). Trying to have a bit of low-stimulation time to wind down before the nap--maybe a book or a song in his sleeping room, with the lights low--should also help.
I realize that this approach isn't intuitive--it seems like babies should get more tired and sleep better if they've been up for longer. But when babies get too tired, their bodies produce adrenalin to help them stay awake. The adrenalin makes them kind of wired/jumpy, so they have trouble making it through their sleep transitions (at 20 min, 30 min, etc.) without waking up. So if you can help them get to sleep before they are tired enough that the adrenalin response kicks in, they are more likely to make it through the transition.
All that said, we still had a fair number of too-short naps. These strategies helped a lot, but it was still a developmental process that got better with time and consistency.
Congratulations on your baby boy, and best of luck with the sleep stuff. Hang in there!
With good wishes for a little shut-eye,
Juliet