2 weeks post ACLR and still can’t sit without full leg being supported

Post ACLR with patellar tendon. Brace fully extended.

I can lie down fine or sit upright with my leg along a couch for as long as I want. But I can only last max 30 min sitting with just a chair and a stool+pillow to rest my ankle on. My leg falls asleep and it feels like my knee is working overtime to stay up.

Naturally, I tried adding another stool+pillow right below the knee. But somehow even that’s not enough. It seems like every part along my leg needs to be supported in order for the pain to stop (i.e. on a couch)

Is this normal? Anything I can do outside the standard rehab exercises (leg raises, flexion, isometric quads) that would help? It’s pretty discouraging to not be able to sit at the dining table for long.