Hi there
Just stopping by to say I have posted to your other thread here:
Baby cries as soon as being swaddledand that a strict PUPD method is not a suitable at this age.
If LO is crying a lot of course pick up, use your shush/pat method and continue until he is calm, put down in the cot and continue shush/pat all the way to sleep if necessary. If he is used to nursing to help him sleep it is normal to take some time to learn to sleep without that prop.
Some night feeds are still normal at this age so if it has been 3hrs+ since last feed then I would go ahead and feed him otherwise he will wake again shortly after.