son is breaking my heart

so I was with my sons father for 6 years. e split a year ago and he got engaged and had been absent from my sons life for 11 months. he finally started calling and helping out of the blue and I let my 5 year old fly out to him and his fiance for 10 days. he had a great time and tells me all konds of stories about his time there. but now everytime I get onto him or he gets in trouble he tells me hed rather live with his dad. that he loves his dad more. that he has more fun with his dad. mind you his dad is a good person but he never helped much with both our kids when he was around. and up until 2 months ago I was doing it all on my own. i finally just snapped and have my son sittong in his room crying because I finally had enough. I yelled. I yelled a lot abd really loud. I'm tired of being told he wants to live with his dad. I am the one who has done everything for him. I'm the one sculpting him to be a good kid.

why is it he had 10 days of absolute fun with his dad now his dad has the image in his head of how life would be if he lived with him. I am always down to my last dollar because I have rent and bills and gas and food and stuff for my kids to pay for. his dad lives with his future in laws and only has car insurance to pay so he has extra money to blow when my son goes there... it makes him not like his everyday home life. I just dont know what to do.