Hi Jordie

there is nothing that you can take over the counter that is safe for third trimester (even antihistamines). There are the prescription drugs like valium etc, but your Dr will not really want you to take them unless absolutely necessary.

I have insomnia too, and developed anxiety as a result. In the end you will sleep eventually, so my best advice is to not fight it (eventhough you want it so much) and sleep when you can. It is just realising that you won't get a full night's sleep and making do with what you can get. If you can't sleep then get up and do something and try again at little later on.

All the best