Thanks to all! Using all these answers I managed to fly & land without the tilting! (Issue resolved!) (issue was infact the weight of the fuel)

To add to what the other are saying, SCEL is about 1,500 feet above sea level, and probably hot. Very hot. This affects the `density altitude` (the apparent altitude from temperature, pressure and weather conditions rather than the actual height above sea level) and changes drastically the speed settings for the load. 

 

All this, combined with the weight is probably contributing to the issue. To echo what others are saying , the Learning Center is a really good training tool as it is sim-specific and will use the default aircraft to show you what correct practices and procedures you should adopt.