Horse BAD mounting problems?

Please do not suggest a trainer i dont have time for one...Alright so i recently got a swayback mare named Hazel and she seems to buck while mounting.Its no BIG deal i mean its only 1 foot of the ground.But thats not all put your foot in the stirrup and she turns her butt towards you!Then you get smashed by a barrel horse butt.When you get on her she behaves doesn't buck or anything.I didn't say this before but the buck is when you get on her quick like you quickly put your foot in the stirrup and get on and she pins and does a mini buck.One more thing she also when you are standing on the mounting block she side steps away.The vet looked at her and said it is not back related so i really dont know what to say.She sometimes lets you on her if you stand on the mounting block with your leg over her for 10mins but i cant wait that long i compete on her and i cant waste 10min please help!This is NOT a horse that walks away thats not bucking.She bucks not walks away i do not want to know how to stop a horse from walking away i want to stop bucking thanks!