How would i be able to eliminate all sideways motion?

I know it is weird question, however that is what it i need.

Something like a vertical stabilizer, however with jets, cause what i am building is so insanely fast and complex, wings do not work anymore.

I need to make a code that makes it so when i turn horizontally (yaw), the kinetic direction of travel always backwards or forwards not to the side. The rest i do not need since i will be using a gyroscope, and the up and down needs to be free.

The reason i ask this is because of my terminator snapping turtle, it needs to go in a straight line to precicely hit its target like a missle at atleast 10000 mph. The problem is that when it keeps its momentum from the previous kill, it keeps doing this spiral, and like a balarina tucking in her arms starts spinning faster untill it exponentially spins itself upside-down and crashes my game, cause the auto aim code of that creation is 5 full sheets of a4 paper collectively doing a meltdown.

And that is for each of the 14 gyroscopes.