Nothing more I can do 😭

It has seriously been three hours of me trying put my son down for bed. He’s 6 almost 7 months! He usually goes to sleep around 5pm and we wake up at 5 AM, but these past couple weeks have been so hard to get him down. He showed all the signs of tiredness three hours ago so I was going to lay him down, he fell asleep so fast, but the moment I laid him down for his crib he started screaming. I have gone in there more than 10 times to soothe him, then rock him & lay him down. Every time I lay him down he wakes up and starts screaming. It’s really been three hours and now he’s just screaming in there because I cannot keep doing this. I don’t know what else to do. I am a single mom and losing it.