Should/Can I retract a paper that has fatal math error after this paper has been accepted, presented, and released in the proceeding? This paper has been accepted, presented in the top conference of computer science, and released in the proceeding since last month. However, recently, other readers find a fatal and ridiculous error in the proof. For this fatal error, I think I cannot amend it. Even if it can be amended, some important claims and nearly all proof steps will become total different. 

Something to stress:

1, My claims and other proofs are motivated by the wrong proof rather than the experiments.

2, I then used experiments to demonstrate the correctness of the claims.

How can I handle it?
For a journal paper you could either retract it, which means to "unpublish" it, or you could add an erratum, i.e. a short note where you explain what parts of the paper are wrong (and how to fix them, in case you know it) and which parts are still correct. 

If I understood your case correctly, it seems like an erratum stating that the mathematical proof is incorrect, while the experiments still support the claim, would be appropriate.