Very unique job situation, need good resume advice!

Hello,

I need a good advice regarding the organization of my resume because my job situation is quite unique. I went to business school, so I know how to properly write a resume, however, I am stuck here. I am hoping someone can help me to organize it better.
Okay, so:
My family is foreign and my dad has a small business working with another country. It is a very small and simple business where he works with a couple of clients in Russia who purchase medical equipment/auto/boats from US. We help to export them. I've been helping my dad since high school and when I went to college every summer I would come home and work with him. (lets call his company X) In between I had an internship and other jobs in college. When the whole crisis happened and tariffs raised in Russia my dad found a new channel and decided to rename the company (so now this company is called Y) Since I graduated from college I've been officially working for him because he asked me to stay and help him with the now new company. I've gained a lot of experience and now I want to start looking for a job in my major. So in my resume it says that I've been working for company X (summers 2007 - 2009) then school internships and other jobs in between, then company Y (the renamed one) 2011 to present. I've been advised to not separate the two because it is the same company, however, I do different tasks, work officially and gain a lot more experience.

Here is the question: Should I combine the two? Company y (formally company x)? Should I mention in the interview that it is a family business and I worked there for the past year because my dad really asked me to? I had issues during interviews where they did not take my experience seriously because I am working with my dad. I believe I gained more experience here than during my other internships. How do I explain to the interviewers this whole situation?

I really appreciate your time and advice!

Thank you