I would not feel guilty. It could have been a heart attack. You can not blame yourself. You didnt do anything to your cat..... I think nature just took its course and be glad you had 6 years together.
I was hoping someone has some advice..... Well my cat went to the bathroom and when i saw her come out she had a string of mucus hanging from her rear. She didnt seem to notice. She is totally herself. I checked the litter box and all seems normal other than the fresh poo she had just made...it...