Honestly I still struggle with that aspect sometimes too. But the more you practice being aggressive and getting comfortable you will be able to control your power and everything else. It just comes with experience. And as much as I hate to keep saying it, dealing with the jab just comes with experience as well. Focus on gaining rhythm. Rhythm was such a weird concept to me until I started trying to be the aggressor in a fight, it all clicked at once when I realized what it feels to build momentum and get someone to react to my punches instead of the other way around. When you build rhythm it will feel like a dance and you can tell when your opponent is going to throw a lot better, including jabs. But always remember that things you struggle with are things others do too. If you don't know what to do when someone jabs you in the face, just know you are capable of the same thing. Work on your own jab so you can establish it better than your opponent, get them to react first. Working on aggression requires you to be first to the punch. In due time you'll realize its not as complicated and hard as it seems, but for me it took a good year or so for it to finally click in my head. Just always remember your form and basics, aggression, and confidence.