The worst thing you could do is give up, I believe that game-development is one the most self-motivated areas of work there is due to all of the general skills required. I highly suggest that you continue to study mathematics, as that is an important aspect in game development and computer programming in general. I completely understand the frustration you have, I just turned 16, and was doing the same thing you are right now when I was your age.
My advice to you is to take it easy on learning everything at once, maybe just make some simple graphics for now. You should play around with blueprints more (blueprints can do a lot) , and just try and make a few things, maybe start out with something small, and as you become more confident, work on something more advanced. If you continue with game development at this age, you have a real chance at having a very successful future, because like Jezcentral mentioned above, you couldn’t ask for a better start.
Oh, and one tip: Break your sentences up into paragraphs.