Before prostatectomy (robotic keyhole) I loved cycling, I'd do 40-50 miles on MTB (round south Herts bridleways so not that extreme) and some days cycle from Watford to work in London for fun. After the op I had a lot of general discomfort (sore balls, pain in penis and perineum) for some time so didn't even think of bike until 7 or 8 months after (op was autumn 2019). I just kept walking 3-5 miles a day. When I tried bike again it was OK but would be sometimes a bit sore riding and uncomfortable after. I had to stop (another story had to pick up a motorbike that fell off stand and nothing felt right for weeks after. Then it was wet and winter, I couldn't face starting ). Tried again 2021 gave up as not comfortable. In 2022 I started again surgeon said try and push through it, which I did and it worked, and I kept going through winter even. I'd feel some discomfort after riding but it got less and less. Now I'm up to 50km around roads of South Devon (a lot more up and down than Watford St Albans area) and it feels fine, and generally discomfort has gone . I'm not going as far as I used to but I was 59 when I had the surgery and at that age it takes time to regain fitness after a long lay off.
It took lots of experiments with seats and riding position and patience , building up and accepting some discomfort at first
Originally had Fizik saddle that was a no-no. Tried an ISM seat which was good to start. Now I use a Specialized Power expert which is more conventional but with a big cut out and is comfy
I treated myself to new Scott Scale (hard tail) carbon MTB in 2022. That brought back the discomfort after riding, changing to shorter stem and bars with a bit more rise helped but mostly just getting used to new riding position. After several weeks it was fine. 2023 I tried road bike (Trek Domane which is endurance geometry and pretty compliant). Sure enough was a bit uncomfortable afterwards but soon settled, now I find that much the better option, despite the skinny tyres. The weight difference is a revelation!
I suppose the story is be guided by your body but don't give up, take your time