I need help...

Last night my husband-to-be, who I have been dating for 4 1/2 years and have a 7 month old son with, told me that the reason he hasn't wanted to have sex with me or touch me for the past 7 months, aka, since our son was born, is because "it's not exciting anymore. We won. We had a kid. It's like when you play your video game. How many times have you played it since you beat it? Once? Maybe twice? It's not fun anymore" so I asked him if he still wanted to marry me and he said "I'm done having this conversation, you know better." And got up and left and hasn't talked to me. I don't know what to do... he won't talk to me about it and I've tried everything I can think of to intice him to want to have sex with me, but he stops it before I even have the chance to start anything.... I literally have no chance... I need advice, badly. 💔