TIFU by checking my Ex’s Phone

I am going to start this off by saying that this entire experience has felt straight out of a campy, low-budget romance novel, and honestly I am still wrestling with the fact that this is my actual life right now. Also, for context, I am 28F.

So this all started about 3 months ago when I got a text message from an unknown number. It literally just said:
“Check his phone: [My now Ex’s phone password].”
I originally thought it was just some random asshole playing a cruel prank on me. But the longer I sat with it, the more the pieces started fitting together. At the time, my Ex (27M) was coming home way later than usual a couple of times a week. Like, coming back at 1:00 AM--mind you, he gets off work at 10:00 PM. He kept telling me his boss was taking the team out for dinners and bar hopping.
Then I remembered finding a random hair tie in the passenger seat of his car a week prior. I buy very specific heavy-duty hair ties because I have thicker hair, and regular Goody ones don't work for me. When I saw it, I was in total denial and just assumed I’d borrowed it from a friend. Hindsight bias is real, guys. I was profoundly ignorant.

Also, how the hell would an unknown number know his exact passcode if they weren't close to him? I didn't even know his passcode and we had been together for three years. So, I waited until he got into the shower and tried the code. It worked--which I was desperately hoping it wouldn't. I found ample evidence: text messages, DMs, and photos proving he’d been cheating on me on and off for a year with multiple women. I screenshotted everything, texted it to myself, deleted the proof from his phone, and cleared my text history. I couldn't bear to sleep next to him (we’d been living together for 2 years), so I packed a bag. When he got out of the shower, I told him my friend Ashley had an emergency, gave him a kiss goodbye, and left. I drove around the block, parked, and sobbed for 30 minutes before calling Ashley and crashing on her couch. The next day, I confronted him. Long story short: I did end up punching him in the jaw. I wish I could say I regret it, but it was cathartic as hell (10/10, if you see him in the wild, highly recommend). All jokes aside, I was crushed. He begged me to stay, but I packed my entire life into a storage unit and started couch-surfing.

Here is where I'm a little lost and have gone a little crazy

I work for his dad. That’s actually how my Ex and I met in the first place--he used to come visit his dad at work during lunch. Some quick backstory: His dad, let’s call him "John" (44M), had my ex when he was very young. The baby mama left when my ex was 3, and John raised him while running his own local mechanic shop. Four years ago, John hired me as his receptionist. John has always been an absolute sweetheart. During my first week, I offhandedly mentioned how I like my coffee, and every single morning since, a fresh cup has been sitting on my desk. My delusional ass genuinely thought my ex was waking up early to bring me coffee until I came in early to work one day and caught John in the act. My Ex probably doesn't even know my coffee order.

John was devastated and furious with his son when everything blew up. They got into a massive, screaming fight over what my ex did to me, which made me feel guilty--I hate being the cause of family drama, even if my ex is a douche canoe. My ex hasn't stepped foot near the shop since.
Naturally, working for my ex’s dad felt insanely uncomfortable. Two weeks after the breakup, I texted John my resignation: "I'm so sorry, blah blah, putting in my two weeks, blah blah, things are too awkward, etc."
John legit just texted back: "No."
Which... fair, I’m the only receptionist and he only has two other mechanics. But then he called me and said he refused to let me quit unless I had another job lined up, because he knew I didn't have a stable place to stay and needed income. So, I stayed.

A week later, John overheard me telling one of the mechanics that I was running out of friends' couches and was genuinely considering sleeping in my car. John immediately offered me the guest bedroom in his apartment. I initially refused because it felt wildly inappropriate, but eventually, desperation won out. His apartment is amazing. I have my own bedroom, private bathroom, and a walk-in closet. But John’s behavior hasn't changed--if anything, he’s somehow even sweeter. He leaves a mug of coffee and toast on a small side table outside my bedroom door every morning before he leaves for the shop. Last weekend, when I went out drinking with my girls, he literally drove out at 3:00 AM to pick us up so we wouldn't have to take an Uber. When I woke up horribly hungover, there was Ibuprofen, Tylenol, and a giant glass of water on my nightstand, and he was in the kitchen making me a full omelet.

So yeah. The original title of this post was supposed to be "TIFU by having a massive crush on my cheating ex-boyfriend’s 44-year-old dad." I am sitting in his guest room right now typing this while he is down the hall, and I am losing my mind. The job market for finance in my area is completely dead right now, I can't afford my own place yet, and I am living under the same roof as a gorgeous, ridiculously attentive DILF who treats me better than his son ever did.
Reddit, what the actual fuck do I do?

TL;DR: Found out my ex of 3 years was cheating on me via a mysterious text, punched him, moved out, and tried to quit my job at his dad's mechanic shop. His dad refused to let me quit, found out I was almost homeless, and let me move into his guest house. Now he brings me coffee/breakfast every morning and I am falling aggressively in love with my ex's 44yo father.