I feel for you for the frustration.
I remember when I first tried to start a site , I wanted a big online company that will make me a millionaire.
But it's much harder than it seems, and same goes with a clothing line.
Not trying to hurt you or discourage you, but realistically, would one buy a shirt from your site, or from amazon and walmart?
And for a site that promotes products, it will be extremely difficult for it to take off.
Also, have you considered legal problems? Who will ship your products? Do you have a business agent? Who will supply the materials you need? Who's going to help you mass produce the shirts?
But if you truly want to stick to this idea, then I'd recommend maybe selling your products throughout your community, like maybe opening a tshirt business in the neighborhood, and if it's a success, it will grow larger and larger until maybe you could one day buy your own shop and even make it into a major company.
This is the case with most success stories.
Again, I'm not trying to discourage you from your cause, I'm just offering my advice.
But good luck and keep up the hard work!
Jim