Just take it very easy post op. There might not be much to see on the outside but you will have had a lot of cutting and stitching or clamping internally and it is most important that you lift only very light things only increasing the weight very progressively over a couple of months or so, as you will doubtless be instructed. Increase exercise gradually. Also, drink plenty of water and try to avoid becoming constipated by means of diet or in need mild laxatives. Be prepared for leakage which in most cases improves over time but for some may take longer than for others.
Hopefully, surgery will do the job but keep up with PSA tests.
Wish all goes well for you.