How do I get better?

So here's my situation : I play celts/incas/italians mostly, with celts being my current main civ. It's also the one I had the best results with so far. Just as a sidenote, I'm stuck on Voobly since my potatonPC can't run DE. I donplay the new 1.6 Patch, so DE balace is active. Anyways, my goal for now is beating the Hard AI. But for god sake I'm not succesful at it. My current strategy is Drush into FC and Knights, than transition into siage, altough I never get to that point. Usually, even if I get one or two vil-kills, he usually reaches feudal by the time my militia are out, and they're finished by archers or m@a. After that, I get rushed, and even if I get to castle eventually, I already lost my powerspike and my units are outnumbered. I'm already using most hotkeys too. So how do I improve? Yes obviously practice, but I've been doing this for two weeks, and failing. So what other than that?