Help please !

So I’m a first time mom. My son is 8 months old. He was doing great. We were doing great. Almost perfect. He would lay down and fall asleep by himself never cried or anything. This las week has been like hell for me. Almost every time I cuddle him for his nap as soon as he feels I’m putting him down in his crib he wakes up and starts crying. I try to let him calm down and see if he will calm down in his own but he doesn’t. During the day I can put up with it but at night I’m exhausted 😩 and at my wits end. It stresses me out so much to hear him cry like crazy at night when I lay him down. Lately I’ve been taking him to shower with me to see if it helps but it’s the same as soon as a lay him down. I love my son to death. But I’m also feeling defeated here... advice please? Thanks in advance