I had surgery and anesthesia for a nerve block was injected into my femoral artery causing a seizure.  the question? Can I donate blood after this?

Yes. I am sorry this happened to you. The medication that caused the seizure is gone from your system and will nit impact the ability to give blood.
Should be fine. Local anesthetics are relatively quickly metabolized after administration. Unless you plan on giving blood at the same time that you might have local anesthetic inadvertently injected into a vessel, it should be fine to donate, provided you meet all pre-donation criteria.
Yes. The drug will disappear from your bloodstream over a few hours.