sleep training a cosleeping and ebf baby

18 weeks 7 days

At wits end and it’s making me a bad mom to my toddler cause I am groggy all day and surviving on coffee! I follow ww and yet nights are getting worse by the day/night We hold him for first two naps and wear him for the next two. We are on 90/90/90/90 mins schedule. We have tried extending but somehow I think he is on the lower end of ww. Nap 1: 1.30-2hr Nap 2: 1.15-1.30 Nap 3: 40 Nap 4 : 20 mins or 40 mins.
If it’s 40 mins we try to stretch last we to 2 hours or 1.45 else 1 hr. But no matter what we have experienced false starts, 4-5am wakes

Prob 1 - We are using halo sleep sack as he is just starting to show signs of rolling so for now one arm out. That’s starting him and he wa up every 15-20 mins Prob 2- no matter when I put him he is up 40 mins later. Prob 3- motn wake and play (is he really under tired) Prob 4- can I use crib and sleep train together starting next week