Welcome to the boards!
A couple of things:
many moms find it difficult to implement prior to about 8 weeks for a couple of reasons. Mostly because of the quick rate that the little ones are developing. Crying takes a peak at about 8 weeks, so it's a bit easier to do sleep training at that time as they are starting to get more used to the sights and sounds and smells and sensations of this new world.
The important thing right now is to focus on the order of Eat Awake Sleep. Even if the Awake time is only but to do a diaper change.
half an hour is a typical indication of being Over tired so you may need to put your LO down a bit quicker.
Are you still using the swaddle?
Also, have you checked out these FAQ's for helping to extend sleep?
https://babywhispererforums.com/index.php?topic=85500.0This will hopefully help you extend some of the naps. The shorter nap is very normal developmentally and we mommy's generally have to teach our LOs to sleep.
HTH!
Please post more questions after you've read that link!