SITL for a new VTOL airframe

I have a created a new air frame which has a + VTOL configuration. The Gazebo model for the same is also something I have created as in the picture below.

To simplify my job I decided to replace the model’s .sdf and .config file in the default tail sitter model (which has VTOL X configuration) that comes with the Firmware. I also changed the default tailsitters mixer in the posix-config/SITL/init/ekf2/tailsitter from the VTOL X to VTOL + configuration. I am a beginner to using PX4 and this is my first project using it. How do I proceed further?

If I give a takeoff command on gazebo the drone pitches over falls upside down. The log for the same is here Gazebo Log File

Replacing tailsitter can work, but all you really need to do is duplicate all those pieces, but call them something else.

Then to build and run everything together make posix_sitl_default gazebo_tailsitter.