So don't blame yourself at this time. Of course, he died so young, which made us feel very sad. I think the past is the past. Let him go, or you will suffer.
You must have your own reasons for leaving him. As long as you don't regret the decision at that time, don't regret it now. Because there were specific circumstances.
Take care of your life. If you really miss him, you will cherish your present life. As long as you live well, he will feel at ease in heaven.