I just wanted to post to commiserate. It sounds like you mostly need just a listening, sympathetic ear. So yeah -- THOSE JERKS!! I can't believe how heartless and callous they were. Talk about piling on and making a horrible situation, somehow even more horrible. There are really no redeeming words for such asshats, and I hope if you do decide to re-enter the workforce even after FI, you can find a genuine, supportive workplace. Because you deserve that.
I'm really, really sorry about your dad. My thoughts are with you during this difficult time.
Please do look up a counselor or therapist in your area to talk to. I have one and she is invaluable. They can help give you an additional support "pillar" when you most need it, and experiencing these two losses so close together would be overwhelming for most/all humans. There is no shame in asking for help. There are a lot of mixed up, complex emotions going on with a sudden, shocking death, and especially under those circumstances. And the loss of your job/identity on top of it can really yank the rug out from under you. Don't feel like you have to deal with all of this alone. This is exactly what really smart, caring people have studied and practiced for years and years in order to handle. They are professionals for a reason, and in my opinion, worth every penny. Your mental health and happiness is worth it.
Side note, it is normal to go through a few therapists before you find a good fit. Don't write off the idea completely if it isn't great on the first try. It's all about finding someone who you "jive" with and can see building trust and camaraderie with that person. Some people just simply don't fit, and that's ok. Just try again.
Good luck.