I won't say which accent is better because, although I'm biased toward my own American accent, I also adore the British accent and could listen to it all day long!
I think that you need to decide which accent to pursue based on what is most commonly spoken in your area of the world, in your industry (if you'll be using it for work), where you'll travel (if you'll use it for traveling), and also what your personal preference is. If British English is more common in your country and in your workplace, it makes sense to stick with UK English. If American English is more common, then think about switching. I know you said that American English is "more common" but I wasn't sure if you meant in general, around the world, or in your country or type of work.
But, as the previous poster said, don't give up only because it's hard. Some things are worth the effort. And, to be honest, do you know if speaking American English will come any easier for you?