I am sorry you're confused and frustrated. Take a deep breath and we'll figure everything out
Ok, so the two issues you brought up were:
1. the website
2. the supply chain
First of all, I wanted to ask you a conceptual question. When you're referring to Macy's, were you referring to it as in the layout and feel of the Macy's website or the general concept as the Macy's stores?
1. the website
Did you want to design the website yourself or do you have a budget for a programmer? I think you should be able to learn and create the website for yourself with the help of available tools. It depends on what you envision the size of your project, what you want your site to look like, and the capabilities of the site.
2. Your products supply chain
So you want to create custom designs... Have you thought about whether you will design the designs yourself? who will produce the clothes with the designs? where will you store the inventory? etc. I am sure you will find a dropshipper who would be willing to ship your products on your behalf, but I also wanted to let you know that Amazon offers a similar service, where they can store your inventory in their warehouses and will ship it for you. There are costs associated with all these steps. Have you looked into the numbers?
Let us know what stage you're in, other specific questions, and I think we will be able to help.
Don't be discouraged, you will figure out what you need to do!