I came across these clips to help you change your quilt cover which is something I do personally find difficult. It doesn’t help that I am only 5ft small and clipping these to each corner really helped me. I guess if you can’t find them a large peg or the bag clips would work in the same way.
To help you avoid causing pain while getting into bed, sit on the bed with your arms by your sides. Then lower yourself on one side by leaning on your elbow then putting your head down while raising your legs on the bed. (Hope that makes sense).
When getting out of bed, lie on your side, raise your head then put your feet on the floor and lift yourself into a sitting position.