best bet mate is to do a wheelie instead of stopping and doing an endo, i had this problem aswell and found it hard to get out of so instead of stopping and doing an endo u need to stop and try and do a little wheelie rather than endo and go from there. or just try and do a wheelie then stop on the back wheel then pedal again and stop rather than trying to do pedal kicks try and just wheelie and stop, i dont mean stop for ages just for a short time so u learn to keep going foward rather than back then start to get a kick going