Unfortunately, you would need to redeploy the solution and reactivate. If you have any viable data that you would like to retain (in terms of tasks) you can export it to an XML via the task ribbon while you are looking at the list.
When you say you deleted the CEWP, would I be right in understanding you’ve just deleted this from your one project? If so, you can just create another project site from the structured template, and then use that as a model to create another identical CEWP on the affected site. Once you’ve got the replacement CEWP created, you can then view the contents of the new site’s CEWP as HTML and copy/paste the HTML into the new CEWP on the damaged site.