Is it a big deal, or am I crazy?

Recently I've been feeling way down in the dumps and have been for the past few weeks. Partly because my fiancé and I are buying a house under contract and agreed to let his cousin/best friend, his girlfriend, and her two year old son move in with us (to help us pay bills and because they really needed a place) well to sum it up living with them is less than ideal, it's literally hell. They've been together for 7 months and have been trying for a baby for 7 months. My fiancé and I recently found this out and IMO I think they should have gave us a heads up because 1) our house is only so big with 5 people already and 2) that would be a lot of stress on my fiancé and I seeing as they can't afford their part of the bills as it is. My fiancé doesn't understand how upset that makes me especially since I want a baby and have for quite some time. This past cycle my fiancé agreed to one and now all of a sudden he keeps saying "oh we will have one eventually...", he doesn't seem to care about my feelings or care to understand them and just gets irritated and mad when all I want to do is cry and stay in bed all of the time and do nothing but sleep. I feel like we are wanting different things in life now that push comes to shove and I feel myself slowly detaching from him... I honestly don't know what to do anymore so any advice, positive words, or encouragement would be so nice right now 💔