How much of an age difference is too much? Am I too young to handle this?

You are legally an adult. And as such, you get to make your own decisions now. If you are close with your family, I can see how this might complicate your ability to make an unpopular decision. But they aren't the ones who have to live the consequences of your decision. In my opinion, 19 is still pretty young. But the disparity between 19 & 23 (or 20 & 24) is not that great. If there is an honest and deep love connection between you and this guy, then I don't think you should let your family dictate what you do from here. It's your life. Mistakes are inevitable. But would you rather give up on him and regret it? Or take a leap of faith and be wrong? I hate to put love in those terms :(. I mean, the other side of it is that you guys live a happy and fruitful life. But this is not about anybody besides you and your guy. Certainly weigh what others have to say (the good and the bad). But be strong and true to yourself by making the decision on your own.