How I can stop overthinking?

Overthinking is a common sign of anxiety. It sounds like you are having difficulty sleeping and you aren't feeling happy. It sounds like you have identified that communication is something you need to work on with your husband and now you might be feeling anxious over how to solve the communication barrier. I think there are several things that you can do to help you put aside the anxious feelings or worry that you are having.

Have you told your husband how you feel? Sometimes when there is a communication barrier, people stop communicating. Is it possible that you are apologizing for things and he doesn't even know you were angry or upset?

If you are clearly communicating with your husband and still find yourself ruminating or worrying excessively, it's time to stop your thought process and change it. Overthinking starts with a thought trigger. Maybe you can begin journaling some of the thought triggers that you have. This will help you address some of your larger issues of worry in your life. For example: Are you worrying about kids, finances, fidelity, etc. 

Once you have identified the thought trigger, you need to decide if it is worth your time and effort to continue worrying about it. Is the thought trigger something that can be solved or is it something that cannot be solved? For example, worrying about a test tomorrow. If you have a test, you know that no amount of worrying will change the outcome of the test. However, worrying about getting in a car accident can be solved by buying car insurance. 

You can try setting a worry timer. Note when you start worrying about the issue and give yourself 20 minutes. At the end of the 20 minutes, it is time to set aside the worry. If you feel yourself start to think about the worrisome issue again, you can tell yourself that you already worried about the issue and it is time to move on to something more productive. 

If you have not done so, I encourage you to reach out to a therapist for help. A therapist can help you wade through some of your worrisome ideas and help you determine if some of the things you are worried about are valid or just misplaced fears. A therapist can also give you more tools to deal with your worries and fears. I wish you the best as you continue to deal with this issue.