I'm upset that my dad goes on a lot of business trips
Why are you upset your dad goes on business trips?
It's so inconvenient not being able to get in touch with him for a long time
That isn't fun. However, your dad has to earn the lifestyle your family enjoys.
I know and I do appreciate him but it still sucks.
It is a good think you want to spend time together. Try to make the most of things when you do hang out.