I had L4-L5 surgery in Nov 2019. Began riding the trainer after a couple of weeks and had to raise my bars to get more upright. Progress was slow, but steady. You'll get there. By six months, pretty damn good as long as I don't over do it with yard work or moving furniture.
I still ride long and hilly rides, but with different expectations. Not "lower," but different. No more hammering, but more fun.
Keep up with the physical therapy too.