Quoting ❥Charli:" this post is just all kinds of sad.... OP, save money and move to your own house. that way you will ... [snip!] ... reason they see fit. Either way, that room still needs to be clean. and it don't sound like your SO is going to do it "
Sorry that you are going through so much. Totes w/ lids are gonna be your bestfriend. We moved into a smaller house last year and I have zero room for anything so I had to buy like 7 totes. My king size bed takes up most my bedroom with like 2ft walking space, it sucks we are hoping to move in May. Your SO was so wrong for what he said to you, it would never have gotten messy if he was picking up, smurf if you are working and he is home, his ass needs to be cleaning but since he hasn't you have no choice but to clean it yourself, for the sake of your child.
Good luck OP, hope things get better for you!