My occupational health nurse recommended that all my seats, chairs, and toilet seat should be raised by about 4". She'll scream at this but I found all that completely unworkable. After half a day I went back to all the seat heights that I was used to.
I'm naturally very self-conscious of my balance and centre of gravity, especially when lifting things or changing position. I never sit with my lower legs vertical, when my thighs are horizontal my feet are either angled forwards, or tucked back. When getting up from a lowish seat I slide to the front of the seat and tuck my feet under my hips, for a controlled vertical lift.
Having seats raised so that the height of the seat was the same as my foot to knee length meant I was far too high to be able to tuck my feet under me! It also felt like I was straining my back to get up, as I was having to deadlift my hips by straightening my knees with vertical lower legs, rather than having my hips above my feet positioning my centre of gravity more naturally vertically above my feet.
It may or may not work for you, but you could try sitting in the unadjusted seats that were most comfortable for you before the op. Your body is used to them, trying to sit and get up from something unfamiliar may be creating more harm than helping.