Can I withdraw my consent later?

Yes. A Data Principal has the right to withdraw consent at any time, and the Act requires that withdrawing be as easy as giving it. Withdrawal does not invalidate processing that lawfully took place before it. Once consent is withdrawn, the Data Fiduciary must stop processing and must cause its Processors to stop as well, and should erase the personal data unless retention is required for a legal purpose. Practically, this means withdrawal has to propagate through your systems and your vendors, not merely set a flag in a database.