Feeling really down and cant sleep just need some advice?

my partner of 7 years and i have a 21 month old daughter together and we decided to have a nother baby we tried last month and now he has told me he dosent want to try anymore and has changed his mind it has let me gutted i have been crying for ages. i just eel so let down.... i dont no what to do, because TTC consumes you ater a while it becomes your life filled with us and down and excitment then its taken away from you, i feel let down by him what can i do, we tryed to talk but it just became an argument