I have always liked writing, like some kids draw or dance or sing. However it can still be a struggle. The way to improve your writing is to write every day and to invite criticism. Look at criticism as feedback, helping to make you better. Give yourself a goal of writing for 20 minutes a day, regardless of whether you want to or not. Then, the next day review what you wrote critically. Think about what would make it better. Then write another 20 minutes.
By the way, grammar and spelling are important tools. The more you know about them, the better. And it helps to read good writing by others.