Help, this is my fourth time trying to quit my extra job!!

I have a main job, and two secondary jobs cleaning people’s houses.

One is a newer, a small two bedroom 1 bath home.

The one om trying to quit is a McMansion 5 bedroom 5 bathroom, library and exercise room beast.
They both pay the same amount. 80 dollars for a full clean, 60 for lighter days.

I don’t wanna be at the McMansion anymore! Is started as a favor to my now ex boss. I since switches jobs 2 more times and still continue working that house. It’s too much for me, I’m only one person.

I confided that I’m on the spectrum and basic things are hars for me, and they’ve been super kind and patient with me. I like that. Other people get impatient trying to deal with me or they can’t hide their eye rolls or disgust on their faces. These people are nice, they give me extra money on Christmas, will sometimes give me food and have brought back gifts from their home country.

I appreciate their patience and kindness, and the cleaning tips I’ve leaned working there for 4 years.

But I don’t wanna anymore!!! The first time I quit it was because I couldn’t clean all 3 floors anymore in a single day. To compensate the switched it up to 1 and a half floors a day. They other two times it was because I just kept getting exhausted even with the adjustment and feeling like the low of the low foe still not being able to clean all they want.

Monday night it hit me hard in the middle of my regular job that I don’t wanna go there anymore. It caused stress That made me feel physically ill but I knew I wanted this change. Since I started my new job I remembered how stressful a McMansion is and how I’m doing more work but getting paid the same at the old house.

I tried to come up with a good reason that I couldn’t be talked out of and decided I would say I wanted to go back to school(a lie), I wanted to change careers and no longer be a cleaner(not a lie), and that I’ve been having health complications from cleaning for 6 years so I wanted to find something less physical(also not a lie)

It didn’t work!!! No it didnt!

They asked what I wanted to go for, I said I dunno, I wanna research programs for those with autism and the like.

They said I could just work weekends instead(NO) And I could just wait and keep cleaning until I start classes (NOOOOOO)

They glossed over the other things I said and I left, because I have my regular shift tonight and wanted to go home and rest.

What do I do?!?!? I’m so thankful to them and happy they like me but I don’t wanna be there anymore so badly. It’s too much for me, even if they were to raise the pay I still don’t want to do it I have so much stress there.

What’s a polite but sure fire way to leave that wouldn’t burn bridges??? Please help me I can’t keep doing this