Your letter is very touching, and your question is difficult to answer. With two obviously very bright sons, it is perhaps inevitable that you would be very concerned with their cognitive development. I’m sure I don’t have to tell you it is unusual for children to be able to count at 18 months. But perhaps the focus on such achievements is too intense in your family. Ethan might not be so frustrated if you put less emphasis on early reading with both boys. Whatever happened to Ethan at 19 months probably affected his motor and muscular development also. By finding enjoyable ways to help him with balance and coordination, you might be helping him more than by trying to teach him to read. Since you plan to home school, it should be possible for you plan the teaching activities for Ethan at a pace and a level that will not result in a sense of failure for him. Good luck. And perhaps with time—and plenty of love and support from his family and help from appropriate professionals—he will regain some of the potential he appears at this time to have lost.
Our parenting advice is given as suggestions only. We recommend you also consult your healthcare provider, and urge you to contact them immediately if your question is urgent or about a medical condition.