I now have six 8 inch " elephants feet to raise my bed up enough so I can get off ot wo=ithout too much hassle . Prior to getting them I used blocks of gate post cut to size and glued in pairs .have you got a solid table then lay on that with cushions from the settee as its more solid compared to the sofa
otherwise get trimmed board under the sofas cushions to stiffen them up
if your too low you have issues but if your above center height above the knee its also easier to push up to stand when you get your legs out of bed ...