How do I manage the guilt of leaving my students behind?

Your feelings are valid.

It helps to remember:

If you have been strong enough to navigate a career as a teacher, you are also strong enough to navigate your transition.

If you have been clever and creative enough to create learning experiences for young people, you are also clever and creative enough to apply your skills in new ways.
If you have been a champion of your students dreams and interests, you can also be an advocate for yourself.

Your students are resilient, and they will be ok in your absence because they had you as their teacher.