Arsh, it's sad to hear you need to be subjected to that kind of talk. It's also unfortunate your sister-in-law, as a fellow woman, doesn't show sensitivity and has lived in your house with your family and doesn't show the respect you deserve. It's good you went to the gym to get out-of-the-house. My husband's brother lived with us for a few months once and it was terrible. I don't know how you've managed it all this time! It seems at a minimum it'll be nice to re-claim your house for yourself and your daughters.
When listening to your husband and SIL talk about their new space you almost have to recite a passage from the Christian bible. Jesus said "Father, forgive them, they know not what they do." That captures what appears to be happening with your husband and SIL with their cruel actions. They are acting foolish and don't realize what they're doing. You can wish evil upon them or you can wish for forgiveness for their foolish ways.
When are they actually moving out? It seems this process is taking a long time. When my husband moved out the first time he packed up and was gone within one day. You're enduring a lot of additional suffering as they slowly pack and plan their move. I hope it happens soon.
Arsh I do believe your situation will get better soon. Your husband appears to hold a lot of resentment against you and he appears to enjoy making you suffer as a way of getting back at you. Once he's gone he'll lose that control over you and the whole situation. The dynamic will change. At some point your husband will realize he got what he wants and then what? I believe then he'll start to reflect on everything. Even then he may want to relish in his freedom and enjoy his new life for a while, but slowly he'll start to feel the loss of his family, he'll miss the comfort of home, he'll be hit with the stigma of being a divorced man in your culture, he'll discover the burden of caring for the children alone when you're not there, and he'll come to the realization that he can't just stop by your house every day (if you make it clear he's not allowed in). He'll be a lot more humble as he goes through this whole process. If you can just hang on and keep doing what you're doing it just has to get better soon.
