I recently deleted my answer to this question because I was proven wrong. Meanwhile, I earned upvotes. Is there a way to get these votes deducted, as I feel that I did not deserve them?
If a post has a net score of less than 3 or has been on the site for fewer than 60 days, when the post is deleted the reputation it produced is also removed. This might not happen immediately; it could take until the next day (UTC). Your answer was at +2 when deleted so you should see an adjustment.
If those conditions aren't met, I don't think you can have the rep changes undone. The reason is that, in general, if your post was live for that long and upvoted enough then it did help people, even if later conditions changed and the post was removed -- site rules or scope changed, a better answer came along and you want to defer, things changed and invalidated a once-correct answer (more likely on the technical sites than here), etc.
If you feel like you have undeserved reputation, you might consider lowering it, while helping the site, by offering a bounty. I've sometimes done this to reward existing answers that I feel have been under-valued by the community. We have a lot of great answers, so if you're feeling too reputation-rich I'm confident you can find a place to spend some of it.
Reputation changes from bounties, votes (both up and down), and acceptances on deleted posts (including answers to a deleted question) are nullified. (Exception: Reputation earned for posts with a score of three or higher, and where the post has been visible on the site for at least 60 days, is retained).
You're all set. It may take a little time for your reputation total to change, due to caching.