I was diagnosed with stage four S. Gale cancer in 2019. I recently had my six your CAT scan and I am still showing no sign of reoccurrence. The thing that was a game changer for me and staying elevated at night was purchasing 4 inch memory foam mattress, topper, in addition to my wedge and extra pillows. I just sit on my bed for about a minute before I lay back, and I have had no problem sliding down. I did find myself still rolling off during the night, and I have stopped that by making sure I’m always hugging a pillow. I truly hope that this will work for you.