We're 3.5 months old. Sleep regression is starting to show itself. We…

We're 3.5 months old. Sleep regression is starting to show itself. We can't put the baby to sleep without tantrums and tears ? especially daytime naps, I don't even recognize my child anymore, he used to fall asleep peacefully on my chest. It's been getting worse for over a week now ?. He only falls asleep when you pick him up, rock him for 15-20 minutes and still fusses, pushes away. We try not to exceed his wake time. Please share your experience ?????? How did you get to SZZ? What methods did you use?