Hello aero-Sapphire,
Do you have your code on a github somewhere? I may be able to provide you with better assistance if I’m able to see your repository. Also, is your aircraft a fixed-wing or rotorcraft?
You may be able to use the optimAero SITL without the UAV support package. Take a look at step 6 on our repository. There’s a bash file that you can run to set up the PX4 build toolchain. Feel free to shoot an email to info@optim.aero if I’m slow to respond on this forum.