Lost a cat to an apartment fire I'd probably caused.

Hello. I rescued a cat (about a year old) on March 7th. I initially was going to give him to my parents but we (me, my husband and son) immediately fell in love with him and decided that he would stay with us. We called him Tisha. He was the sweetest cat I've ever known, clever, calm, beautiful. On Monday though he lost appetite and drank no water and we saw worms in his poop. I dewormed him and syringe fed him with puréed food mixed with water and he seemed much better on Tuesday but still showed no appetite and was mostly lying under the computer desk in one of the rooms. On Wednesday morning I fed him and left the mini blender I used to make his food with charging on the desk he was lying under and we all went to work and preschool. I also closed the door to his room so that he wouldn't jump on beds and soil them with worms eggs. When we came home in the evening I was first to open the door to see if Tisha was doing well. I sensed the smell of burnt plastic, the light didn't work, I rushed to the door to Tisha's room, opened it and saw ashes flying out of the door. Everything was black with soot. Tisha was lying under the table all covered with soot and stiff already. Only one room had damage because the door was closed and the fire had not a lot of oxygen to spread and most of the damage was on the desk where the blender had been charging and around it. Now I can't stop blaming myself. I'm mostly okay while I'm around my family or busy working, but the moments I stay alone I start thinking all the what ifs and should haves. I should have taken a day off to stay with Trisha and check if he was recovering, or ask my parents to come and check on him, I shouldn't have left the blender charging without supervision, I should have dewormed Tisha before he lost appetite, I should have brought him to a vet as soon as I took him in, I probably should have given him to my parents or shouldn't have rescued him at all. Any kind words would be appreciated, maybe other people's stories and how you've been coping with the feeling of guilt of causing a loved one's death.