It is obvious that you are trying, cinnamon. I read the posts and they don't really sound like they are conveying you aren't trying, but rather encouraging the continuation of what you've started.
People are motivated by different things. I think I would buy a little stopwatch of some kind, and start timing how long it took myself to get up that hill, and keeping track of it. Maybe try it every other day. Maybe you will have to stop a few times to catch your breath, but maybe a few months from now you won't have to stop at all, and ****, maybe some day you'll be running up that hill!
As others have said, you have to start somewhere. And you did it! You aren't a failure at all. You pushed yourself and you made it up that hill, even though it exhausted you. That's the type of will and strength you need!
When I tried to break into a jog from walking, for the first time, I thought I was going to die right then and there. It was depressing, and I can relate to that feeling of failure. But I had to realize that I'm not just going to wake up one day and be fit. Nobody is going to magically bless me with a young body and heart and a body full of muscles. I've got to work at getting that back.
So please, don't feel defeated by this. Feel *proud*.