When do they sleep full nights??

Please send help 🙏 I left a DV a few months ago, with a 3.5YO and 15MO. I am currently struggling to get them to sleep in their shared room! ATM they are sharing a bed with me - I work 3 days a week because I have to right now, and I am getting next to no sleep. Both cry when I put them to sleep in their room. TIA.