|"i just cleared it a week ago and tried Speedfan to use it better"|
Speedfan isn't going to help. The cooling vents MUST be clear. You didn't state how you cleaned it but you should blast the vents with compressed air - 1st from one direction, then the other. Also, when using the laptop (& especially when gaming), make sure there's plenty of clearance for good airflow into & out of the cooling vents. Do NOT place the laptop on a soft surface such as a couch, bed, carpet, your lap, etc. It should be on a hard surface such as a table top & it might help to prop up the back slightly to allow better airflow. There are plenty of different cooling stands available too if you wanna go that route.
Also, the Asus N55S isn't considered a great gaming laptop but it would depend on your configuration. You didn't say which games you play but keeping the game settings & gaming resolution on low or medium will lighten the load & help keep temps down.