Yay! I finally figured out how to make my own banner. Ok, I didn't really make it. I just found a website that did it for me using an illustration I drew on an app called Paper; choose a font etc etc. but it's my very own banner. I did it using this site and the app I used to draw the flowers can be found in the Apple app store.
I love the Paper app. This what what the full image looked like: