I don't mean to disappoint you, but I'm not sure there is anything you can say that will help and I doubt you understand how CVC 22350 was being applied here.

CVC 22350 basically says there will be times when conditions are such that it is not safe to drive at or below the posted speed limit. Based solely on what you posted, it would appear the officer believed that you were diverting your eyes from the road to check your phone for a long enough period that it was unsafe to drive at whatever speed you were going. If you look at your citation there will be a box marked "Safe Speed". The number in that box is what he believed was a safe speed given what you were doing.

It will be incumbent upon you to prove to the court that given due regard for weather, visibility, the traffic on, and the surface and width of, the highway, you could spend as much time looking at your phone as you did, while traveling at whatever speed you were going, and not endanger the safety of persons or property.

It will not be enough to simply make a blanket declaration that you did not endanger anyone and that your speed was safe. You will have to carefully articulate why and how no one was endangered and your sped was safe.

It would have been better if you had requested informal discovery and obtained a copy of the officer's notes and because it was CHP, a copy of their audio recording of the officer's contact with you containing any incriminating admissions you may have made to him. This way you would have a better idea of what you are defending yourself against.