well.....if your going down from other guys hits.....try going down a bit lower and speading you feet wider then you'll be more stable....
its just like when someone pushes you.....if your just standing there straight your gonna go down, but if you have one foot back you most proberly wont. the further you have that foot back the chances that you will go down become smaller
and bend your knees, that should help out...with your dodging speed
now im not a boxer...but i do
Muay Thai, so yeah, i have learnt how to box
and practice, practice, practice, just remember if you cant slip their punches there is always parrying.