That is unfair that your family is taking advantage of you like that. I've never worked for a family member, but I used to work for a family friend and it actually made things more stressful because I was worried that screwing something up or wanting to switch to a different job would be construed as a reflection on the personal relationship that I had with my employer/family friend.

If I screwed up, it wouldn't just reflect on my competency, but it would damage the interpersonal relationship I had with this person. So I was constantly paranoid and stressed and obsessing over minutia.

Now that I work in a more traditional office setting, I find myself much happier. The work-life balance is a lot healthier, and there is no role ambiguity.

If I were you, I'd definitely keep sending out resumes. Good luck!