fighting sleep/not going down

Anyone else struggling at bedtime? My little guy will be 4 months next week and up until yesterday he was great at bedtime. I would get him in his jammies, feed him, pray with him and then put him down (half the time he was still awake) and he would be good for atleast 5 hours, sometimes more. Bedtime being between 630 and 730 depending on his tiredness ques. The last two days he will not go down. I'll rock him or walk around till he is alseep and then as soon as I put him in his bed he wakes up. Last night it took me 3 hours, tonight I've been trying since 7 and it is now 930. I'm so frustrated! I think we are in the middle of a huge wonder week leap or something, but I'm seriously loosing my mind!