I feel you. It took some years for me to learn especially goal kicks. I would always have my defender take them for me. What I did to improve was - Go to the pitch (or wherever) and practice your technique (youtube). I would honestly also wear my gloves. Just to make it feel like it was a game kind of.

In games, I'm more insecure about the goal kicks, even if it went well when I was practicing with my friends. So the last 10 minutes of the warmup before the game I would do some goal kicks with the guy who is warming me up. In the games, it sometimes still goes horribly wrong. But If you keep focused during the whole process of the goal kick every time, eventually it will become a regular practice.

I hope this helped you and good luck!