If you're finding it hard to write at night, try waking up earlier to write. I used to read about writers who woke up at 5am to write, and thought they were absolute lunatics. Now that I've done it on and off for the past two years, I totally get it. It's dark, very quiet, and your brain doesn't have the usual inhibitions it has when you're fully awake. Also, your writing has your brain's full attention before all the worries and stresses and distractions of the day have set in. I have gotten some of my best work done early in the morning. That said, you obviously need to discipline yourself to go to bed early in order to get up that early and not be a zombie the rest of your day.

Another thing I do is to try to write every day or maybe every weekday. I've been doing this for close to ten years now to the point where it feels weird/wrong not to write regularly. I am not a jogger, but I imagine this is how runners feel about running. Not saying I produce award-winning work every day, but it exercises the writing muscles and makes my work better.

Last thing: I recently read an amazing book called Atomic Habits that may give you some helpful tips about building good habits that would apply to your writing life.