the challenges of severe autism;low mental capacity with rigid thinking

today/monday,self and two support staff were out food shopping in asda,before we left for asda had taken two haliperidol anti pyschotic pills as normal which always do before going anywhere to lessen severe challenging behavior and its causes.
we got in asda and had planned to buy a few things,including a pack of four ice creams and sweet corn as treats for the children [AKA binky and mabel].

for some reason there is a specific lump sum of money for spends each day with three pound of that for activity money but it has always been spent on anything because am not able to do activities every day, recently we got a new house manager who does everything by the word-which means changing a routine of mine that has always been there because she was on shift as support staff today with a regular support staff of mine,and as often happens staff always act mega strict when around managers.

was in the ice cream isle when was told that had got to the maximum money and had to have three pound left over for an activity that didnt exist,so to get ice cream was going to have to take away somethings from the basket-these were all items that were on a visual list in mind and was impossible to wipe and become unfocussed on-its impossible to remove or swap any.

they started removing goods and had felt very very bad because of it, started hitting out, punching everything as well as head banging and was trying to stop them from taking the stuff out the basket;was sat in the wheel chair thankfuly so did not end up throwing self to the floor and head butting it like old times but ended up kicking,punching and biting support staff who were invading the basket,and then threw something from the basket on the floor in frustration.
am very sorry if had hurt them,and will always feel guilt for any actions towards others but their attitude towards self really hurt,they dont truly understand this aspect of self,and assumed was being challenging for the hell of it.
they said they were going to take em/self back to the car without any shopping so quickly put the breaks on the wheel chair and got really frustrated so more behavior came out,ended up having another two pills of haliperidol.

the thinking is,its a visualy planned mental list,and removing any of it makes no sense to self plus its very distressing to cope with.
they usualy calculate as we go along so we dont get this problem but they made a guess at it this time.
wish people were more open minded instead of using threats.