How Do I tell him I love him?

When is the right time to tell him I love him...? Also how do I do it? I've already put myself out there once with the last guy by telling him how I feel only to receive his unrequited reply which then Led to a dragged out affair where I allowed him to use me physically and emotionally once he knew that I cared more and had more to lose if I left. So, I'm kind of scared to open up to my new bf. Should I just wait for him to do it so that way I know he feels the same way? I'm kind of scared to go through that rejection and pain again by giving him that power