Get-to-Sleep Strategies

When my Husband and I were going thru our separation, our son became more and more attached to me. He suddently started to throw fits more often, and he was having a very hard time to go his bed. Soon after my husband left, he started going back to his normal self, but until today bed time is the most difficult part of the day. He wants to only sleep in my bed and with me. Usually I have let him fall asleep in my bed and then I take him to his room, some other times I stay with him - in his bedroom - so he can get use to it, but for some reason, when I do this he stars singing, playing, and he does everything but going to sleep. This is really frustating, for me, and sometimes I think I am going to lose my temper. What can I do to have him go to bed in his bedroom????