I can rewrite it. The one who applied first can declare your patent invalid, unless you use it earlier than them, in which case you can declare the other party's patent invalid. The appearance of utility models is different. This cannot be a reason for you to defend yourself, because this lawsuit will only focus on utility models, which protect the internal structure. The utility model you both applied for has a similar structure. It seems that the other party came prepared. It was one year earlier than you. The structure and function are similar. Your chances of winning are really slim.
Your defense can basically be based on the fact that the design is your own, but happens to be similar to the other party’s, and you do not know that the other party has applied for a patent. Moreover, you have also successfully applied for it. You can ask the Patent Office to grant you patent rights. Since it is similar, why can the application be successful? Since the application is successful, why can't it be sold? The subsequent court arguments will be up to you.
It is recommended that you find an intellectual property lawyer, because the current situation is really not good for you. If you have to pay compensation in the final court decision, at least hiring a lawyer will save you a lot. Moreover, if you hire a lawyer, you may not be compensated, and the lawsuit may not be without room for maneuver.
Good luck.