Well they say, "If it doesn't kill you, it makes you stronger"  but usually it kills you.
HA! Just kidding.  I find dark humor to be strangely comforting when things look like they can't get worse.  I just lost my 86 year old dad less than a month ago and I still have my mom (who has dementia and doesn't even know who I am) living with me. She can't remember he's passed away, and I can't forget it.  Some days the challenges are just overwhelming. Of course the normal ration of ka-ka still hits the fan too: New roof had to be put on, car had to have over $1000 in repairs, medical bills for both parents are huge and overdue, portions of my deck are rotten and have to be replaced before I fall through, etc....etc......etc......BLEAH!
After the funeral for your dad, things will again settle into a 'normal' routine and you'll feel better. Of course 'Normal' is just a setting on your dryer.
Hang in there, wait it out, it does pass.  My favorite verse in the Bible is "And it came to pass......"  Wouldn't it be awful if it came to STAY?