Toilet regression in ASD adult. Desperate need of help

Hi . Im just generally looking for some advice from people who may have experienced the same or similar issue alongside somewhere to just cry in all honesty

I have been the full time carer and guardian for my sister since 2015 when both our parents passed away. We also lived with our grandmother

My sister and i have a very good relationship and historically are very close. Hence why i decided to take over her care. I work full time and we fell into a really nice routine with a good care team that came in the morning and afternoon allowing me to work and keep some of my independence.

That was before 2022.....my grandmother's health started to decline and around the same time i noticed my sister having bouts of urinary incontinence. This increased over the course of the year and then started to include occasional faecal incontinence also . My grandmother eventually ended up passing away and all hell broke loose re. The incontinence. The thing is my sister attends a day centre and has had NO issues with going to the toilet independently or asking for help when she needs it. She has completely and utterly regressed at home. This has led drs to rule out any medical issues. Aside from my grandmother being unwell and passing away nothing else changed in her routine

I recently was able to purchase my dream house and we moved in over the December holidays but ill be honest in the fact that i just want to walk out into the water thats by it. I tried my best to keep as much as i could as similar as possible and we were able to slowly transition across to the new house and she SEEMS really happy and settled, knowing where everything is (including the bathroom)

However, my sister has had near constant incontinence unless i get her to go to the toilet hourly or half hourly (even then she may not go and then go to sit downstairs only to have an accident ) .She doesnt need to wear incontinence pads to her day centre but ive had to put them on at home because i cant keep up with the washing and now the potential risk of getting poo on everything. I dont know if that is giving her mixed messages too. Im worried im just doing everything wrong

I have booked another drs appointment for Monday as i think she may have developed IBS as a side effect to one of her epilepsy but im terrified ill just break down and say i dont want to care for her anymore....would she just be better off somewhere else.

Its just really really horrible. I'm only 36 and i just want this to end but i have no idea what to do. Can i potty train an adult...do i just wait it out? I absolutely hate my life at the moment and the stress of last year now coupled with this is making me withdraw from her (which i know probably isn't helping)

Ps we have no other family.