No More Dance Aerobics

So Thomas seems to be getting worse and worse when it comes to bedtime and sleeping. I'm sure we've probably done this to ourselves, but it has gotten to the point where you have to bounce him while walking around and patting his back, with his soother, sleep sheep, swaddled for like 45 mins before he will go to sleep. And that's after feeding him and bedtime stories. And I'm not doing it anymore. It's ridiculous. Does anyone have any wonderful suggestions of how to get him to go to sleep easier? He's 4 months old now and he still eats every 3 hours all night long - any suggestions on lengthening the time between feeds? Some people purport to have babies younger than him that sleep for upwards of 9 hours at a time. Are they lying? If they are actually being truthful, what is their secret? Is it too young for sleep training? We will be leaving in about a month and he's bound to be thrown off by all the travel and sleeping in new places, etc. Should I not even bother doing this right now?