Hi there,
Sorry you're having trouble in the night. I have been there and am still there sometimes so I know how hard it is!
I suspect that your DS is waking in the night because he is overtired. You should be looking to have at least two long naps, and possibly a short catnap at the end of the day if needed.
He has to be woken from his morning nap and we struggle sometimes with the lunchtime one
Did I read this correctly? Do you wake your DS after 30 min. of sleep in the morning? If so, I strongly recommend you let him sleep. Once his routine is established then you can stray from it once in a while let's say for playgroups etc. If you just typed something incorrectly and he's simply waking after 30 minutes, I suggest doing pupd to get him back to sleep. 30 minutes is not restorative and this starts the day on the wrong foot. Awake time is very important at this age as well. If your DS isn't awake long enough he may not be tired enough to sleep for long, and if he's up too long he might be too overtired to stay asleep. Have you tried awake time of 2:15? That worked well for my DS at this age. Also, babies usually like a shorter A time before first nap.
If you can get that first nap to go longer, preferably to 11am, then the rest of the day would go much better. Then second nap could run 1:30-3:00/3:30 with bedtime no later than 6:30. At his age awake time shouldn't be much longer than 2.5-2.75 hours.
You may also want to look at the pupd board to make sure you're doing it correctly. At your sons age, if he's able to stand in the crib, then you are supposed to wait for him to stand and just do the PD part. Babies over 6 months settle faster out of your arms.
okay, dinner time here. HTH