The fiery feeling when lying on the OP side you describe is exactly the feeling I had, like having a small bonfire inside my thigh. For me, it slowly subsides with time.
When sitting in a regular chair my groin starts to hurt. It's much better now a days, but sitting for a longer time, like at a dinner, still gets uncomfortable. Sitting in my Baden Baden doesn't hurt at all, in fact I've been using it since day 1

In the sofa I used, and still use, a big yoga pillow to put my leg on sitting, like, across the sofa. There's not much room left for my man, but he doesn't mind

I'm also familiar with the swelling, still have some, but my swelling is more all across the affected area. My OP side is still bigger then my non-OP side, but oh so slowly I think it's fading away. I will actually try some targeted massage next week hoping it will aid the circulation and swelling.
I also read about all those being able to run a marathon 3 month after surgery and there I was, still on crutches 8 weeks post-op. They might exist, but I bet they are oh so rare

What I've learned from this forum is 'your body, your healing journey'.
I know you are going through a hard time, I did as well. For me, I started to feel better when I completely got rid of the crutches. It felt like my life was returning and I was able to see some real progress.
It's a roller coaster but you will get there. Just remember to be gentle to yourself