Ah, grammar! Normally, this is either ESL students’ most liked or most disliked part of learning English.
Well, whether you like it or not, it’s not going away, so the best thing to do is to study until you start to get a feel for English grammar. I often tell my students that grammar may start in your head, but your goal should be to get to move to your heart. Once you can feel a language, even at a basic level, it becomes a part of you, and it starts to feel like this is a tool that you can use, instead of something that is controlling and limiting you. This doesn’t happen overnight, but with hard work and patience, it does happen.
It is worth remembering that feeling too much stress makes any kind learning difficult. This is especially true in language learning, so try not to put too much pressure on yourself. Relax, have fun, and laugh at your mistakes. You’ll do better next time!