A long walk on Sunday is way too early, after op he needs lead walking for a week, then still not a great deal of off lead time, we found our dog was crawling the walls too, so we did some lead walk, then let him off for just 5 mins to have a bit of a run to burn off the excess. Slightly swollen is probably fine, after all if you've cut yourself it never goes down that quickly. keep an eye on it, and if it starts to look red, or pussy take him straight back.
Try doing some training exercise, this might help him stimulate his excess energy, such a difficult time! I know when our was going through this I didn't quite know what to do with him either.