If you carry on like this, you'll end up looking old like me. [There, a little Lu Meng joke.]

In all seriousness though, you'll be alright. It's hard to shake your doubts, and I don't know if you'll ever be able to let go of all of them, but I don't think anyone can avoid all uncertainties when considering to pursue a romance. Well, unless you're naive. But you're not, and that might actually help your relationship in the long-run.