Gayakarna, you are not to late
My son started at 4 and we have successes day by day.
You will get results but that shouldn't be your focus or you will stress and miss the joy. Focus on the imput rather than the output. Some kids show what they know quickly others make you wait, it is different for each child. By exposing him to all this information now you are doing wonders for his brain and ability to learn later in life. Feed his mind with all you can find that he enjoys. The results will come in time, try not to be temped to pull them from him. Your journey has just begun.
Keep doing what you are doing, for as long as you both enjoy it.