Ashley-
While the hospital bed would be the best solution, since various positions can be achieved & different mattress toppers can add extra comfort (esp. an alternating air mattress? that gives slight "turns" throughout the night to relieve pressure), until then have you tried using a "turning sheet"?
This would be a little harder in a queen bed, but still better than what you are doing now. Take a flat sheet & lay it on top of the fitted sheet when making the bed. Don't tuck it in anywhere.
When you need to turn him, take the end of the sheet opposite to the side that you will turn him to. Pull the sheet over him & pull sheet toward you. So, if he wants to turn to face the middle of the bed, take the side of the sheet on "his side of the bed", fold it up & over him. Then you would need to go around & kneel up on the bed. You should be able to "roll" him over in one move. This may take practice to see how hard you need to pull, because of his size & your's.
It is helpful to position pillows first, before turning. One running lengthwise between his legs which you can shift slightly, once turned, if you have to. An arm pillow is easy to place when already on side.
Turning to the opposite side is easier since you will be at the side of the bed you are turning towards. Flip the sheet from the middle of the bed (or your side) over him after placing pillow, go around to "his side" of the bed, and pull sheet toward you.
When doing this, first be sure he is not too close to the side to begin with, or he may just fall out. So, you would first pull him, using the sheet, (and satin sheets are good for this as they slide easier) slightly to the middle of the bed, then turn the sheet over him, go around to the other side of the bed & turn. Position arms as needed.
As I read this, it sounds confusing. Think of when you have cookie dough, putting it on wax paper & shaping it in a roll. You bring the paper up & around the dough and then roll it. You do the same with the sheet. Does that make sense to you?
It would be so much easier with a hospital bed for several reasons. The whole bed could be raised so you don't have to bend down while doing all the pulling & turning. It is twin size, so you wouldn't need to climb up on the bed when turning to the one side. And, I'm not sure if he has breathing issues yet, using a bipap, but certainly being able to adjust the head of the bed would help as well.
Can you compromise- swap out your bed for a hospital bed for him & a twin bed for you?
That way you can still be "next to him", but have the ease of the hospital bed.
Keep trying to persuade him to do this. You are doing way more work than you need to; it can be, and should be, at least a little easier for you.
Hope this was helpful; hope you get some sleep!