Hay nako, yan ang third trimester insomnia talaga, a few of us went through that around 6-7 months, super nakakafrustrate! Try naman the usual stuff like warm milk, relaxation, or sleeping on your left side, pero honestly if it's really affecting you, best to mention it sa OB mo next visit para ma-check kung okay lang, basta alam mo na normal ito sa pregnancy kasi ng hormones at physical discomfort.