Addie, I can't help you with the design, but I do feel your pain and I watch you struggling the same way I have many times. I'm not a designer. I don't pretend to be one. I don't know fonts, I can't pick fonts, and I'm not good at layouts.
I do, however, have a fairly critical eye. I look at signs, fonts, and layouts EVERYWHERE I go. Restrooms, menus, airports, strip malls, strip clubs, hotels, roadside food stands. You name it, I pay attention to it and have for years.
I'd love nothing more than to be able to do what some of these people seem to do so effortlessly. I've read a number of books on layouts, way finding, signs, etc. I look through google images all the time, looking back and signs starting in the 1800's. I watch old western movies and pay attention to the signs on the hotels, general stores, saloons, etc. I have a great interest in it all, but after only 5 years or so in this trade, I still don't pretend to be able to do that stuff.
You know what my limit is on what I'll design? Something free for someone that lost a dog, or possibly a family yard sale sign. Oh wait, I just did a banner for a family member the other day. That's it. That's what I'm qualified to do.
I also believe that your sign speaks volumes about your business. I don't believe I'd be doing anyone justice if I "doodled up" something and scroll through fonts until something made me happy. This is their brand. It's their store, it's their life. I personally believe it demands to be done right. Right by someone that understands that.
It's fine to have the passion and interest. I think that's healthy, but I think you also need to know that you can't just throw things out until something works.
You've spent a ton of time on this project already. Money lost. Even if you get the job, you've already lost money. There are so many people out there with so much talent that are giving very reasonable prices. You might want to think about using them and just continuing to watch what they do and learn.
I can say, in my opinion, you think you're going to get this down or get to a point where you can do design work sooner, rather than later, but in my opinion, you're on a path that's much longer than you might expect. As I mentioned earlier, I've been watching from the sidelines for about 5 years and I still don't believe I could charge for my effort and feel like I knocked it out of the park. Until I can, I'll hire people that can do that right out of the gate.