My daughter is 7 months & cries a lot when i put her down in her crib to sleep and throws herself around. shes not use to sleeping alone. what do i do?

Train her: Crying is the only way kids can tell you their opinion at this age. Crying is not harmful to babies who don't have a history of heart or brain problems. So have a soothing bedtime ritual then put her down and walk away. Let her cry it out even if it is for 1-2 hrs this will gradually decrease over a day or two and she will be trained. Most important is not to let her see you when she is crying.