Can i black out personal details like DOB and SSN on the documents that i submit in discovery?

You have a right of privacy in your medical records and employment records. To be discoverable, they must be "directly relevant" to a cause of action or defense in the action, and there must be no other way of obtaining the information contained in them. In addition, third parties referred to in those records (e.g., authors of letters of recommendation, sexual partners, et al.) also have privacy interests in information about them that prevents you from disclosing it without their consent. You also have a similar right of privacy in your "personally identifiable information," such as DOB, SSAN, bank account numbers, credit card account numbers, etc. In your formal verified response to the demand for production/inspection of documents, you need to assert such objections as you may have to the production, including the protection afforded by your rights of privacy under Article 1, Section 1, of the California Constitution and other applicable statutes. Since you apparently are representing yourself, you should have a lawyer review the demand for production/inspection of documents, prepare the formal response for you, review the documents responsive to the demand, and redact [black out] the appropriate portions of those documents.