I have an 8 year old TB mare hat I purchased the end of February. I have her a couple of weeks to settle in them started our training. She loaded right up in the trailer alone and with other horses. In a two horse and I have a four horse. Three weeks ago she just flat out refused to load. I tried every method I know - pressure from a whip with a bag ( not hitting her but moving it at her hind quarters), ropes, work the round one then try to loaf,two guys holding hands behind her like loading into the gate at the track, food, loading with another horse. She just shut down. I put the trailer in the paddock and fed her in there for a week. She would follow me right in and I could get her to load with the halter. Gave her a week off and just did some ground work. Tried loading her yesterday and she just stops. I can put one foot up for her and then she just decides to come in. She is not scared, she shuts down with pressure. Any advice here?