I just wanted to make mousse. It's a 35% fat cream. It literally says it's made for whipping chantilly in the package. I have chilled it, i have used a pinch of salt, I have put sugar. Please help me I don't know why it won't get fluffy, it only becomes a mixture of clumpy parts and liquid parts as if I'm making butter and separating the fat from the water, which i am not. Please please help me

edit: thanks for the responses! i read everything at the time and was able to make it. i think the main problem was the high temperatures where i live (summer in a tropical country...), so everything worked when i put the bowl and an unopened bottle in the freezer at minus 24 degrees for about 30 minutes. it turned out really good and airy.
oh, and i now have 0,5 kilos of sweetened butter sitting in my fridge to be eaten as fast as possible before it spoils, yay... 🥲