Avoiding Feedback On Stage - Technical

Hey guys, 

So I need some advice. I play with a boss RC-30 loop pedal, an electro-acoustic guitar and a single microphone ( no specific well known brands). I find that when I am playing, no matter which way I face the amp both my guitar seems to vibrate and my mic picks up the previous loops and becomes distorted resulting in feedback and unwanted noise. 

How can I layer a multi-layer track without getting these unwanted reverberations and this feedback? Is it to do with my amp positioning or do I need a different type of mic which won't pick up surrounding sounds?

Thanks!