Yep welcome to The Contrast Issue. Now you can go back through some of the discussions and see if any of that works for you. I'd say, try preflashing first and foremost, and expect it to increase the sensitivity of your paper by a stop or so.

The other thing, which is blazingly obvious but seldom stated, is that you can meter the contrast of your scene and know straight away whether a paper neg is going to work under "normal" exposure. In a low contrast scene you can get wonderful results. In a an 8 stop scene, well... and of course you can filter blue if that might tighten up the contrast in your scene.